Genetic Algorithms mimic the evolving technique of nature to better fit populations to a certain environment. Despite this technique has proved its adequacy in several fields, its application in Aerospace is still limited, mostly because of the high quantity of acceptability criteria that the design
must pass and the amount of design parameters. The presented paper explores required GA architecture’s adaptations to be applied in highly restricted systems such as those commonly found in Aerospace applications. The proposed GA was applied to the design of an Aircraft Engine’s Axial Casing bolted joint following static strength restrictions as per FAR 33 regulations. The set of Elitism,
interdependent geometric restrictions, Crossing, and Reproduction modules proved the applicability of
the presented multi-objective GA architecture under 14 restrictions for normal, limit and ultimate loads.
As it is described, the conversion is quickly achieved due to the shortage of the search space; therefore a
modified Variable Crossing per Scheme is proposed to expand the diversity of the genome to compensate
the relatively low impact of the Mutation module. Finally, the process and solutions found were compared against the traditional design process, showing the feasibility of this technique in complex applications in terms of quality of the solution and developing time.
Optimization is a method of searching of best available value for a given objective function w.r.t constrains. Airplanes always need improvement in their design as part of evolution and survival.
1. The document describes the finite element analysis of a static wing box test rig design. A basic test rig model was created and analyzed in ANSYS Workbench to evaluate stresses and deformations.
2. The initial analysis found deformations up to 0.8mm, exceeding design criteria of 1mm maximum. The model was modified by adding diagonal struts between components to reduce stresses.
3. Analysis of the modified model showed deformations reduced to 0.6mm. A further modification with additional struts reduced the maximum deformation to 0.53mm, demonstrating how design changes can improve structural performance.
The Development of Design by Topology Optimization for Additive ManufactureCallum McLennan
This document is a final report submitted by Callum McLennan for his third year individual project at the University of Exeter. The project explores using topology optimization to design parts for additive manufacturing. Specifically, McLennan optimized a jet engine loading bracket to reduce its weight while maintaining stiffness requirements. He manufactured and tested an iteration of the optimized bracket. McLennan also investigated the effects of design domain and mesh size on the optimization output. The optimized bracket reduced mass by 45% while maintaining a safety factor of 5. Mechanical testing validated the optimized design. An iterative approach to defining the design domain was found to be effective. Mesh refinement increased detail but did not improve performance.
This document discusses several papers on the topic of topology optimization. It summarizes the abstracts of three papers. The first paper discusses applying topology optimization and manufacturing simulations to aircraft component design. The second paper discusses designing smart composite materials using topology optimization to optimize properties like thermal expansion coefficients. The third paper surveys procedures for dealing with common numerical instabilities in topology optimization like checkerboards and mesh dependencies.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
This document discusses topology optimization applied to automotive chassis design for weight reduction. Two chassis types are optimized - one for a spider vehicle and one for a coupé vehicle. The optimization minimizes mass subject to constraints for bending/torsional stiffness, crashworthiness, natural frequencies, and local joint stiffness. Six test cases are considered that incrementally add more constraints. Results show the optimized chassis masses decrease as more constraints are included. The optimized layouts provide innovative, efficient designs for lightweight automotive chassis.
Diseño, análisis y optimización de chasis de coches de carreras por su rendim...ELKINMAURICIOGONZALE
This document discusses the design, analysis, and optimization of racing car chassis for structural performance. It describes how a space frame chassis design was chosen and modeled in CATIA software. An analysis of the chassis design was performed using finite element analysis in ANSYS to evaluate stresses and deflections from front, rear, lateral and rollover impacts. SAE 1018 steel was selected as the material for its strength, availability, and weldability. The analysis found maximum von Mises stresses of 193.112 MPa and 272.391MPa from rear and front impacts respectively, which provide safety factors above 1.4. The design process and analysis aimed to achieve a rigid yet lightweight chassis for improved racing performance.
This document discusses alternative lightweight materials and manufacturing technologies for vehicle frontal bumper beams. Three composite materials - GMT, GMTex, and GMT-UD - were characterized and evaluated through testing for their potential use in bumper beams. Quasi-static tensile, compression, and impact tests were conducted to determine the materials' mechanical properties and impact performance. Finite element analysis was also used to simulate impact loading and compare the performance of the composite materials to existing steel solutions. The results indicate the composite materials, especially GMT-UD, could provide advantages over steel in energy absorption and weight reduction while maintaining sufficient strength and stiffness for the bumper beam application.
Optimization is a method of searching of best available value for a given objective function w.r.t constrains. Airplanes always need improvement in their design as part of evolution and survival.
1. The document describes the finite element analysis of a static wing box test rig design. A basic test rig model was created and analyzed in ANSYS Workbench to evaluate stresses and deformations.
2. The initial analysis found deformations up to 0.8mm, exceeding design criteria of 1mm maximum. The model was modified by adding diagonal struts between components to reduce stresses.
3. Analysis of the modified model showed deformations reduced to 0.6mm. A further modification with additional struts reduced the maximum deformation to 0.53mm, demonstrating how design changes can improve structural performance.
The Development of Design by Topology Optimization for Additive ManufactureCallum McLennan
This document is a final report submitted by Callum McLennan for his third year individual project at the University of Exeter. The project explores using topology optimization to design parts for additive manufacturing. Specifically, McLennan optimized a jet engine loading bracket to reduce its weight while maintaining stiffness requirements. He manufactured and tested an iteration of the optimized bracket. McLennan also investigated the effects of design domain and mesh size on the optimization output. The optimized bracket reduced mass by 45% while maintaining a safety factor of 5. Mechanical testing validated the optimized design. An iterative approach to defining the design domain was found to be effective. Mesh refinement increased detail but did not improve performance.
This document discusses several papers on the topic of topology optimization. It summarizes the abstracts of three papers. The first paper discusses applying topology optimization and manufacturing simulations to aircraft component design. The second paper discusses designing smart composite materials using topology optimization to optimize properties like thermal expansion coefficients. The third paper surveys procedures for dealing with common numerical instabilities in topology optimization like checkerboards and mesh dependencies.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
This document discusses topology optimization applied to automotive chassis design for weight reduction. Two chassis types are optimized - one for a spider vehicle and one for a coupé vehicle. The optimization minimizes mass subject to constraints for bending/torsional stiffness, crashworthiness, natural frequencies, and local joint stiffness. Six test cases are considered that incrementally add more constraints. Results show the optimized chassis masses decrease as more constraints are included. The optimized layouts provide innovative, efficient designs for lightweight automotive chassis.
Diseño, análisis y optimización de chasis de coches de carreras por su rendim...ELKINMAURICIOGONZALE
This document discusses the design, analysis, and optimization of racing car chassis for structural performance. It describes how a space frame chassis design was chosen and modeled in CATIA software. An analysis of the chassis design was performed using finite element analysis in ANSYS to evaluate stresses and deflections from front, rear, lateral and rollover impacts. SAE 1018 steel was selected as the material for its strength, availability, and weldability. The analysis found maximum von Mises stresses of 193.112 MPa and 272.391MPa from rear and front impacts respectively, which provide safety factors above 1.4. The design process and analysis aimed to achieve a rigid yet lightweight chassis for improved racing performance.
This document discusses alternative lightweight materials and manufacturing technologies for vehicle frontal bumper beams. Three composite materials - GMT, GMTex, and GMT-UD - were characterized and evaluated through testing for their potential use in bumper beams. Quasi-static tensile, compression, and impact tests were conducted to determine the materials' mechanical properties and impact performance. Finite element analysis was also used to simulate impact loading and compare the performance of the composite materials to existing steel solutions. The results indicate the composite materials, especially GMT-UD, could provide advantages over steel in energy absorption and weight reduction while maintaining sufficient strength and stiffness for the bumper beam application.
Airbus - Topology Optimization Methods for Optimal Aircraft ComponentsAltair ProductDesign
Application of Topology, Sizing and Shape Optimization Methods to Optimal Design of Aircraft Components - a Technical Engineering & Analysis Paper from Altair ProductDesign
Evaluation of Over-speed, Burst Margin and Estimation of Low-cycle Fatigue Li...AM Publications
Aero engine rotor burst evaluation is one of the most important problems to be taken care off, whenever it comes to designing a turbo machinery disc. The consequences of a fiasco can be intense, since the disc disintegrates into multiple pieces and they are hurled away in all the possible direction at high speeds. Due to high thermo-mechanical loading conditions the disc is subjected to varying degrees of temperature from bore to rim. However, the centrifugal force dominates in the disc which ranges from 85%-90% and the rest can be treated as thermal and gas loads. The challenge lies at designing a disc for off design conditions with their varying loads and duty cycles. In present work evaluation of safety margins and low-cycle fatigue (LCF) estimation of an aero engine disc through classical methods and blending the terminologies with simulation engineering to arrive at a probable interpretation of number of duty cycles is carried out. The methodology compares the fatigue parameters involved in evaluation of disc life. The design tool closely connects the flight certification requirement, namely Flight Readiness Certification, Federal Aviation Administration and European Aviation Safety Agency the regulating agencies for safety in air transportation vehicles. Speed regulations through API and MIL handbook for material specification using finite element analysis approach.
This document summarizes a study that analyzed the design of a heavy commercial vehicle chassis through material optimization. Finite element analysis was used to model and simulate a 25-tonne truck chassis made of steel, aluminum alloy, and carbon composite. The steel chassis weighed 392.3kg, had a maximum displacement of 105mm, and maximum stress of 172.5MPa. The aluminum alloy chassis weighed 138.1kg, had a maximum displacement of 101.3mm, and maximum stress of 148MPa. The carbon composite chassis weighed 84.4kg, had a maximum displacement of 101.4mm, and maximum stress of 162.3MPa. The study concluded that changing from steel to aluminum alloy reduced the weight
This document discusses computational fluid dynamics (CFD) analysis and optimization of geometric modifications to the Ahmed body to reduce drag and lift coefficients. The Ahmed body is a simplified bluff body shape used to model important car-like geometry features. The study aims to investigate how modifying parameters like rear slant angle, boat tail angle, and ramp angle can influence aerodynamic performance. CFD simulations are conducted using various turbulence models to analyze velocity contours and pressure distributions around modified geometries. The document reviews several past studies exploring techniques like rear slant angle manipulation, surface roughness elements, trailing edge blowing slots, boat tail configurations, and base bleed outlets for reducing drag on bluff bodies.
Design and Computational Fluid Dynamic Analysis of Spiroid Winglet to Study i...IRJET Journal
This document describes a study on the design and computational fluid dynamic (CFD) analysis of a spiroid winglet to analyze its effects on aircraft performance. Spiroid winglets are bio-inspired wingtip devices that can reduce lift-induced drag. The study involves modifying an existing spiroid winglet design with a 3600 blended wingtip and conducting CFD simulations to evaluate the aerodynamic performance. The CFD analysis is conducted using commercial software Fluent to simulate airflow around the modified spiroid winglet design. Results are compared to an earlier study to validate the CFD methodology. Preliminary results show the modified spiroid winglet design improves aircraft performance by further reducing wingtip vortices and
IRJET- Static Analysis of Pulsar Bike Frame Made Up of Aluminum Alloy 6063IRJET Journal
This document summarizes research analyzing the static structural performance of a motorcycle frame made from aluminum alloy 6063, as an alternative to mild steel. Finite element analysis was conducted using ANSYS software to model the frame under various static loads. Experimental testing was also performed on a prototype frame to validate the FEA results. The FEA found the aluminum frame experienced less stress than mild steel under the same loads, with a weight reduction of 34%. Experimental compression and impact testing of aluminum 6063 samples agreed reasonably well with FEA predictions. Therefore, replacing mild steel with aluminum 6063 could improve fuel efficiency without compromising frame strength.
The document proposes designing and building a car-mounted thrust stand for dynamic testing of propellers as an alternative to traditional wind tunnel testing. Key details include:
- The setup would allow testing of propellers over 10 inches in diameter, which most universities cannot test in wind tunnels.
- Aerodynamic considerations require the propeller to be at least 5 times its diameter from the car roof to avoid blockage, and the largest propeller to be tested is 10 inches so the minimum height is set at 27 inches.
- Structural analysis shows the design has a safety factor of at least 1.6 under worst-case loads to remain safely attached to the car at high speeds.
IRJET- Topology Optimization of a Lower Barrel in Nose Landing GearIRJET Journal
This document summarizes research conducted to optimize the design of the lower barrel component of a nose landing gear through topology optimization. The research was conducted in three stages: 1) CAD modeling and pre-optimization analysis of the initial lower barrel design, 2) Topology optimization of the lower barrel to maximize stiffness while reducing mass, and 3) Post-optimization analysis of the optimized lower barrel design. Through iterative topology optimization runs retaining 90%, 75%, and 60% of the original material, the mass of the lower barrel was successfully reduced from 14.507kg to as low as 12.579kg while maintaining equivalent stress levels comparable to the initial design. The final optimized model weighed 10.378kg with only 1.88% and 3
This document describes a procedure for optimizing the design of horizontal-axis wind turbine blades to maximize annual energy production and minimize blade mass. The procedure uses three modules: an aerodynamic analysis module using blade element momentum theory, a structural analysis module using finite element modeling, and a multi-objective optimization module using a genetic algorithm. As a case study, the procedure is applied to optimize the design of a 1.5 megawatt wind turbine blade, with the goal of improving its overall performance compared to the original design.
This document discusses a study that explored trade-offs in using low-lift versus high-lift airfoils for the tip region of stall-regulated horizontal axis wind turbines (HAWTs). A blade design optimization method was used to identify the practical lower limit of maximum lift coefficients for tip airfoils between 0.7-1.2. Blades were optimized for both maximum annual energy production and minimum cost of energy. The results indicate that reducing the maximum lift coefficient below upper limits considered increases cost of energy, suggesting higher lift coefficient tip airfoils are preferable as turbine size increases if they have gentle stall characteristics.
IRJET- Effects of Dimples on Aerodynamic Performance of Horizontal Axis W...IRJET Journal
This document discusses research into the effects of adding dimples to the surfaces of horizontal axis wind turbine blades. It aims to investigate how dimples impact the aerodynamic performance of wind turbine blades. The researchers used computational fluid dynamics software to simulate flow over a baseline wind turbine blade design with and without various dimple configurations. The simulations found that blades with dimples experienced delayed flow separation, resulting in enhanced aerodynamic performance and increased power extraction compared to the baseline blade without dimples. Validation with experimental wind tunnel testing of a scaled down model supported the numerical results.
Abhishek V Nerkar has over 4.5 years of experience in product validation and computational fluid dynamics at Cummins India Ltd. He has expertise in simulation tools like ANSYS, GT-Power, and testing activities including noise and vibration testing, durability testing, and combined environmental testing. Currently he is a senior engineer at Cummins Emissions Solutions India focused on thermal fluid simulation and analysis of emissions after-treatment systems.
A Method for Finding Document Containning Reactionary ViewpointsIRJET Journal
The document describes using topology optimization to optimize the design of a front suspension shackle support. It discusses setting up the topology optimization parameters including design variables, constraints, and objective functions. It then performs finite element analysis on the optimized design under different load cases and compares the stresses to the permissible limits and the original baseline design. The optimized design showed a 30% mass reduction while keeping all stresses below limits, making it a manufacturable and improved design for the suspension shackle support.
Chassis 2002 01-3300 design, analysis and testing of a formula sae car chassisELKINMAURICIOGONZALE
This document summarizes the design, analysis, and testing of a Formula SAE car chassis. It discusses key concepts in frame design including load paths, deformation modes, and stiffness targets. A spring model is developed to determine frame and chassis torsional stiffness targets relative to suspension components. Finite element analysis is used to analyze frame concepts. Experimental techniques like strain gauges and whole-car tests are used to validate designs and determine actual stiffness.
Design Optimization of Axles using Inspire and OptiStructAltair
This document summarizes the use of topology optimization at AAM Products to reduce weight and improve performance of automotive axle designs. It describes how AAM uses Inspire and Optistruct software to perform topology optimizations that consider multiple load cases, manufacturing constraints, and target mass reductions. An example optimization of a carrier design is presented, showing a 20% mass reduction while improving gear deflection performance. The process involves defining design spaces, applying manufacturing and load constraints, setting multi-physics optimization targets, and validating optimized designs through hardware testing. Topology optimization has allowed AAM to develop manufacturable, mass-reduced axle part designs that show performance improvements.
IRJET-CFD Analysis of conceptual Aircraft bodyIRJET Journal
The document analyzes the aerodynamic performance of a conceptual aircraft model through computational fluid dynamics (CFD). CFD analysis is performed on the aircraft model at different angles of attack and taper ratios to determine lift and drag forces. The results show that lift force increases with angle of attack up to stall angle, while drag force also increases. Higher taper ratios are found to generate more lift force and less drag force compared to lower taper ratios. The CFD results provide valuable data to evaluate the aircraft design for applications in fighter jets, commercial aircraft, and drones.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Design Optimization of Reinforced Concrete Slabs Using Various Optimization T...ijtsrd
This paper presents Reinforced Concrete RC slab design optimization technique for finding the best design parameters that satisfy the project requirements both in terms of strength and serviceability criteria while keeping the overall construction cost to a minimum. In this paper four different types of RC slab design named as simply supported slab, one end continuous slab, both end continuous slab and cantilever slab are optimized using three different metaheuristic optimization algorithms named as Genetic Algorithms GA , Particle Swarm Optimization PSO and Gray Wolf Optimization GWO . The slabs with various end conditions are formulated according to the ACI code. The formulated problem contains three optimization variables, the thickness of the slab, steel bar diameter, and bar spacing while objective involves the minimization of overall cost of the structure which includes the cost of concrete, cost of reinforcement and the constraints involves the design requirement and ACI codes limit. The proposed method is developed using MATLAB. Finally, to validate the performance of the proposed algorithm the results are compared with the previously proposed algorithms. The comparison of results shows that the proposed method provides a significant improvement over the previously proposed algorithms. Dinesh Kumar Suryavanshi | Dr. Saleem Akhtar "Design Optimization of Reinforced Concrete Slabs Using Various Optimization Techniques" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd25231.pdfPaper URL: https://www.ijtsrd.com/engineering/civil-engineering/25231/design-optimization-of-reinforced-concrete-slabs-using-various-optimization-techniques/dinesh-kumar-suryavanshi
This document summarizes the design, implementation, and testing of an Android game called Foxes and Chickens. The game was developed using strict software engineering processes. Key aspects include:
- The game has origins in South America and the developers sought to create a digital version for Android devices.
- It has two modes (single/multi-player) and three difficulty levels. The goal is for chickens to reach safety while foxes try to catch them.
- The game was tested on several Android devices and is available to download from the Google Play store, receiving positive user feedback.
- Solid software engineering practices like use cases, UML diagrams, testing and debugging were used in the development process
A boy sees a smiling fish and decides to take it home. The fish continues to smile at the boy when he talks, watches TV, and showers. The boy grows fond of the fish but later finds it floating away, so he follows it into the forest and sea. Realizing the fish belongs in the ocean, the boy sadly says goodbye and returns it to the sea, where it will be happier.
Airbus - Topology Optimization Methods for Optimal Aircraft ComponentsAltair ProductDesign
Application of Topology, Sizing and Shape Optimization Methods to Optimal Design of Aircraft Components - a Technical Engineering & Analysis Paper from Altair ProductDesign
Evaluation of Over-speed, Burst Margin and Estimation of Low-cycle Fatigue Li...AM Publications
Aero engine rotor burst evaluation is one of the most important problems to be taken care off, whenever it comes to designing a turbo machinery disc. The consequences of a fiasco can be intense, since the disc disintegrates into multiple pieces and they are hurled away in all the possible direction at high speeds. Due to high thermo-mechanical loading conditions the disc is subjected to varying degrees of temperature from bore to rim. However, the centrifugal force dominates in the disc which ranges from 85%-90% and the rest can be treated as thermal and gas loads. The challenge lies at designing a disc for off design conditions with their varying loads and duty cycles. In present work evaluation of safety margins and low-cycle fatigue (LCF) estimation of an aero engine disc through classical methods and blending the terminologies with simulation engineering to arrive at a probable interpretation of number of duty cycles is carried out. The methodology compares the fatigue parameters involved in evaluation of disc life. The design tool closely connects the flight certification requirement, namely Flight Readiness Certification, Federal Aviation Administration and European Aviation Safety Agency the regulating agencies for safety in air transportation vehicles. Speed regulations through API and MIL handbook for material specification using finite element analysis approach.
This document summarizes a study that analyzed the design of a heavy commercial vehicle chassis through material optimization. Finite element analysis was used to model and simulate a 25-tonne truck chassis made of steel, aluminum alloy, and carbon composite. The steel chassis weighed 392.3kg, had a maximum displacement of 105mm, and maximum stress of 172.5MPa. The aluminum alloy chassis weighed 138.1kg, had a maximum displacement of 101.3mm, and maximum stress of 148MPa. The carbon composite chassis weighed 84.4kg, had a maximum displacement of 101.4mm, and maximum stress of 162.3MPa. The study concluded that changing from steel to aluminum alloy reduced the weight
This document discusses computational fluid dynamics (CFD) analysis and optimization of geometric modifications to the Ahmed body to reduce drag and lift coefficients. The Ahmed body is a simplified bluff body shape used to model important car-like geometry features. The study aims to investigate how modifying parameters like rear slant angle, boat tail angle, and ramp angle can influence aerodynamic performance. CFD simulations are conducted using various turbulence models to analyze velocity contours and pressure distributions around modified geometries. The document reviews several past studies exploring techniques like rear slant angle manipulation, surface roughness elements, trailing edge blowing slots, boat tail configurations, and base bleed outlets for reducing drag on bluff bodies.
Design and Computational Fluid Dynamic Analysis of Spiroid Winglet to Study i...IRJET Journal
This document describes a study on the design and computational fluid dynamic (CFD) analysis of a spiroid winglet to analyze its effects on aircraft performance. Spiroid winglets are bio-inspired wingtip devices that can reduce lift-induced drag. The study involves modifying an existing spiroid winglet design with a 3600 blended wingtip and conducting CFD simulations to evaluate the aerodynamic performance. The CFD analysis is conducted using commercial software Fluent to simulate airflow around the modified spiroid winglet design. Results are compared to an earlier study to validate the CFD methodology. Preliminary results show the modified spiroid winglet design improves aircraft performance by further reducing wingtip vortices and
IRJET- Static Analysis of Pulsar Bike Frame Made Up of Aluminum Alloy 6063IRJET Journal
This document summarizes research analyzing the static structural performance of a motorcycle frame made from aluminum alloy 6063, as an alternative to mild steel. Finite element analysis was conducted using ANSYS software to model the frame under various static loads. Experimental testing was also performed on a prototype frame to validate the FEA results. The FEA found the aluminum frame experienced less stress than mild steel under the same loads, with a weight reduction of 34%. Experimental compression and impact testing of aluminum 6063 samples agreed reasonably well with FEA predictions. Therefore, replacing mild steel with aluminum 6063 could improve fuel efficiency without compromising frame strength.
The document proposes designing and building a car-mounted thrust stand for dynamic testing of propellers as an alternative to traditional wind tunnel testing. Key details include:
- The setup would allow testing of propellers over 10 inches in diameter, which most universities cannot test in wind tunnels.
- Aerodynamic considerations require the propeller to be at least 5 times its diameter from the car roof to avoid blockage, and the largest propeller to be tested is 10 inches so the minimum height is set at 27 inches.
- Structural analysis shows the design has a safety factor of at least 1.6 under worst-case loads to remain safely attached to the car at high speeds.
IRJET- Topology Optimization of a Lower Barrel in Nose Landing GearIRJET Journal
This document summarizes research conducted to optimize the design of the lower barrel component of a nose landing gear through topology optimization. The research was conducted in three stages: 1) CAD modeling and pre-optimization analysis of the initial lower barrel design, 2) Topology optimization of the lower barrel to maximize stiffness while reducing mass, and 3) Post-optimization analysis of the optimized lower barrel design. Through iterative topology optimization runs retaining 90%, 75%, and 60% of the original material, the mass of the lower barrel was successfully reduced from 14.507kg to as low as 12.579kg while maintaining equivalent stress levels comparable to the initial design. The final optimized model weighed 10.378kg with only 1.88% and 3
This document describes a procedure for optimizing the design of horizontal-axis wind turbine blades to maximize annual energy production and minimize blade mass. The procedure uses three modules: an aerodynamic analysis module using blade element momentum theory, a structural analysis module using finite element modeling, and a multi-objective optimization module using a genetic algorithm. As a case study, the procedure is applied to optimize the design of a 1.5 megawatt wind turbine blade, with the goal of improving its overall performance compared to the original design.
This document discusses a study that explored trade-offs in using low-lift versus high-lift airfoils for the tip region of stall-regulated horizontal axis wind turbines (HAWTs). A blade design optimization method was used to identify the practical lower limit of maximum lift coefficients for tip airfoils between 0.7-1.2. Blades were optimized for both maximum annual energy production and minimum cost of energy. The results indicate that reducing the maximum lift coefficient below upper limits considered increases cost of energy, suggesting higher lift coefficient tip airfoils are preferable as turbine size increases if they have gentle stall characteristics.
IRJET- Effects of Dimples on Aerodynamic Performance of Horizontal Axis W...IRJET Journal
This document discusses research into the effects of adding dimples to the surfaces of horizontal axis wind turbine blades. It aims to investigate how dimples impact the aerodynamic performance of wind turbine blades. The researchers used computational fluid dynamics software to simulate flow over a baseline wind turbine blade design with and without various dimple configurations. The simulations found that blades with dimples experienced delayed flow separation, resulting in enhanced aerodynamic performance and increased power extraction compared to the baseline blade without dimples. Validation with experimental wind tunnel testing of a scaled down model supported the numerical results.
Abhishek V Nerkar has over 4.5 years of experience in product validation and computational fluid dynamics at Cummins India Ltd. He has expertise in simulation tools like ANSYS, GT-Power, and testing activities including noise and vibration testing, durability testing, and combined environmental testing. Currently he is a senior engineer at Cummins Emissions Solutions India focused on thermal fluid simulation and analysis of emissions after-treatment systems.
A Method for Finding Document Containning Reactionary ViewpointsIRJET Journal
The document describes using topology optimization to optimize the design of a front suspension shackle support. It discusses setting up the topology optimization parameters including design variables, constraints, and objective functions. It then performs finite element analysis on the optimized design under different load cases and compares the stresses to the permissible limits and the original baseline design. The optimized design showed a 30% mass reduction while keeping all stresses below limits, making it a manufacturable and improved design for the suspension shackle support.
Chassis 2002 01-3300 design, analysis and testing of a formula sae car chassisELKINMAURICIOGONZALE
This document summarizes the design, analysis, and testing of a Formula SAE car chassis. It discusses key concepts in frame design including load paths, deformation modes, and stiffness targets. A spring model is developed to determine frame and chassis torsional stiffness targets relative to suspension components. Finite element analysis is used to analyze frame concepts. Experimental techniques like strain gauges and whole-car tests are used to validate designs and determine actual stiffness.
Design Optimization of Axles using Inspire and OptiStructAltair
This document summarizes the use of topology optimization at AAM Products to reduce weight and improve performance of automotive axle designs. It describes how AAM uses Inspire and Optistruct software to perform topology optimizations that consider multiple load cases, manufacturing constraints, and target mass reductions. An example optimization of a carrier design is presented, showing a 20% mass reduction while improving gear deflection performance. The process involves defining design spaces, applying manufacturing and load constraints, setting multi-physics optimization targets, and validating optimized designs through hardware testing. Topology optimization has allowed AAM to develop manufacturable, mass-reduced axle part designs that show performance improvements.
IRJET-CFD Analysis of conceptual Aircraft bodyIRJET Journal
The document analyzes the aerodynamic performance of a conceptual aircraft model through computational fluid dynamics (CFD). CFD analysis is performed on the aircraft model at different angles of attack and taper ratios to determine lift and drag forces. The results show that lift force increases with angle of attack up to stall angle, while drag force also increases. Higher taper ratios are found to generate more lift force and less drag force compared to lower taper ratios. The CFD results provide valuable data to evaluate the aircraft design for applications in fighter jets, commercial aircraft, and drones.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Design Optimization of Reinforced Concrete Slabs Using Various Optimization T...ijtsrd
This paper presents Reinforced Concrete RC slab design optimization technique for finding the best design parameters that satisfy the project requirements both in terms of strength and serviceability criteria while keeping the overall construction cost to a minimum. In this paper four different types of RC slab design named as simply supported slab, one end continuous slab, both end continuous slab and cantilever slab are optimized using three different metaheuristic optimization algorithms named as Genetic Algorithms GA , Particle Swarm Optimization PSO and Gray Wolf Optimization GWO . The slabs with various end conditions are formulated according to the ACI code. The formulated problem contains three optimization variables, the thickness of the slab, steel bar diameter, and bar spacing while objective involves the minimization of overall cost of the structure which includes the cost of concrete, cost of reinforcement and the constraints involves the design requirement and ACI codes limit. The proposed method is developed using MATLAB. Finally, to validate the performance of the proposed algorithm the results are compared with the previously proposed algorithms. The comparison of results shows that the proposed method provides a significant improvement over the previously proposed algorithms. Dinesh Kumar Suryavanshi | Dr. Saleem Akhtar "Design Optimization of Reinforced Concrete Slabs Using Various Optimization Techniques" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd25231.pdfPaper URL: https://www.ijtsrd.com/engineering/civil-engineering/25231/design-optimization-of-reinforced-concrete-slabs-using-various-optimization-techniques/dinesh-kumar-suryavanshi
This document summarizes the design, implementation, and testing of an Android game called Foxes and Chickens. The game was developed using strict software engineering processes. Key aspects include:
- The game has origins in South America and the developers sought to create a digital version for Android devices.
- It has two modes (single/multi-player) and three difficulty levels. The goal is for chickens to reach safety while foxes try to catch them.
- The game was tested on several Android devices and is available to download from the Google Play store, receiving positive user feedback.
- Solid software engineering practices like use cases, UML diagrams, testing and debugging were used in the development process
A boy sees a smiling fish and decides to take it home. The fish continues to smile at the boy when he talks, watches TV, and showers. The boy grows fond of the fish but later finds it floating away, so he follows it into the forest and sea. Realizing the fish belongs in the ocean, the boy sadly says goodbye and returns it to the sea, where it will be happier.
A Novel Data mining Technique to Discover Patterns from Huge Text CorpusIJMER
Today, we have far more information than we can handle: from business transactions and scientific
data, to satellite pictures, text reports and military intelligence. Information retrieval is simply not enough
anymore for decision-making. Confronted with huge collections of data, we have now created new needs to
help us make better managerial choices. These needs are automatic summarization of data, extraction of the
"essence" of information stored, and the discovery of patterns in raw data. With this, Data mining with
inventory pattern came into existence and got popularized. Data mining finds these patterns and relationships
using data analysis tools and techniques to build models.
This document discusses the synthesis of nano materials using sputtering. It begins by introducing nano materials and describing electron beam lithography and sputtering processes. The document then details the experimental procedure used, which involves using EBL to pattern PMMA resist on a silicon nitride wafer with a desired pattern. Sputtering is then used to co-deposit alumina and silica onto the patterned wafer. Scanning electron microscopy and atomic force microscopy are used to characterize the synthesized nano materials and confirm the presence of uniformly distributed 50nm cubes. Analysis of SEM and AFM images shows the nano materials have a flat surface, good adhesiveness, and low surface roughness.
This document summarizes a study that evaluated the spatial and physical factors of open areas in residential complexes (RCs) in Iran, specifically in the Apadana residential complex. The study aimed to improve life quality within RCs by better understanding relationships between internal and external residential areas. 325 households in Apadana were surveyed about the quality of open areas. Results found that 50% rated open area quality as moderate, 48.8% as desirable, and 0.6% as undesirable. Suggestions are made to qualitatively and quantitatively expand open areas by emphasizing spatial and physical factors and relationships between internal and external spaces.
Trajectory Control With MPC For A Robot Manipülatör Using ANN ModelIJMER
In this study, in a computer the dynamic motion modelling of manipulator and control of
trajectory with an algorithm this has been tested. First after dynamic motion simulation of manipulator
has been made MPC Control. The result in this study we can observe that computed torque method gives
better results than MPC methods. So in trajectory control it is approved of using computed torque
method. In last part of this study the results are estimated forward development are exemined and
suggested. The model predictive control (MPC) technique for an articulated robot with n joints is
introduced in this paper. The proposed MPC control action is conceptually different with the trajectory
robot control methods in that the control action is determined by optimising a performance index over
the time horizon. A neural network (NN) is used in this paper as the predictive model.
Trough External Service Management Improve Quality & ProductivityIJMER
The challenges in Small car project, necessitated improvements in quality and productivity,
right from day one of implementation of project. Detailed studies on external management services,
manufacturing process, various departments involved, and procedures followed were done, and
problems in the existing system were identified and solutions were provided. The object of this paper is to
investigate methods of measuring performance. The subject of this paper is the process of implementing
methods to increase productivity. Methods (procedures) of the study. Pattern during the writing of this
work was used by scientist’s articles information about the measurement and implementation of systems
productivity. Since this work was written with the use of different methods and examples, not all of them
before writing the work were known to me, I want to present a certain part to improve the productivity of
some companies in my country.
This document provides a sample exam for ACC 561 with 50 multiple choice questions covering various accounting concepts. The questions assess understanding of controllership functions, budgeting, costing methods, performance evaluation, and management control systems.
This document contains 5 photos of a dog named Liberty demonstrating different poses and techniques for pet photography. The photos include Liberty demonstrating the rule of thirds, making eye contact with the camera, a close-up of Liberty's paws, Liberty holding a prop, and a straight on shot of Liberty.
This document summarizes and compares various routing metrics that have been proposed for wireless sensor networks. It begins by classifying routing metrics into five categories: topology based, signal strength based, active probing based, mobility aware, and energy aware. For each category, several representative routing metrics are described in detail, including how they are calculated and their advantages/disadvantages. The document concludes by comparing the routing metrics based on their characteristics and provides a table summarizing the metrics.
This document summarizes an experimental study investigating the potential use of LPG as the primary fuel in a medium-capacity stationary HCCI engine. The researchers modified a diesel engine to operate in HCCI mode using LPG as the main fuel and a small pilot injection of diesel to control ignition timing. They evaluated the engine's performance and emissions when running on this LPG-diesel fuel combination across different loads. The results showed reductions in NOx emissions of over 40% at 40% load compared to normal diesel operation, though NOx increased at higher loads. The document concludes that LPG shows promise as an alternative fuel for diesel engines in HCCI mode after addressing challenges of combustion control.
Design and Implementation of Wireless Embedded Systems at 60 GHz Millimeter-W...IJMER
ABSTRACT: Globally, there is a burning desire for a communication system that provides high quality, high capacity and
high speed information exchange and we need to develop an extremely spectrum-efficient transmission technology for the
same. This paper describes a realistic capacity and BER comparison of a robust and secured multiple access schemes and
develops a wireless embedded system at 60 GHz Millimeter-Wave using WiMAX waveform. The system is tested at the
laboratory with multimedia transmission and reception but yet to be tested after mounting on the vehicles. Technical
expertise are developed towards Simulink programming, methods of poring to VSG, IF and millimeter wave hardware, RTSA
use, Data Acquisition and DSP. With proper deployment of this 60 GHz system on vehicles, the existing commercial
products for 802.11P will be required to be replaced or updated soon. Simulation and implementation of the results will
elucidate that a significant amelioration in the spectral efficiency parameter can be achieved using the proposed WiMAX at
60GHz which provides both frequency diversity and spectral efficiency to yield a powerful and affordable solution for superhigh speed/4G transmission and ever-increasing requirement of high throughput in wideband multimedia communications
and ITS in vehicular communication.
Keywords: AWG, C2C-CC, MC-CDMA, VSA, WiMAX and WMAN, 4G
This document provides a practice exam for ACC 422 with 40 multiple choice questions covering various accounting topics such as cash, receivables, inventory valuation, long-term assets, and intangibles including goodwill. The questions assess understanding of concepts like lower of cost or market, methods of depreciation and capitalization, and impairment of intangible assets.
Receiver Module of Smart power monitoring and metering distribution system u...IJMER
In the current situation all the communication is very much important and faster range but
the usage of the power should be less in order to reduce the power and the usage of the sources we are
going for this data transmission through the power lines which is common and much feasible since
power line is used at all homes. In this paper we have concentrated much in the receiver module where
the receiver receives the data through the power lines through which we can know the readings of
amount of usage of power at each homes and also the power theft if it occurs anywhere.by this way we
no need to generate any particular infrastructure for transmitting an d receiving instead we can use the
power line itself.This is the work done in NLC,TAMILNADU india which is very less explained in this
paper.
Investigation of Effects of impact loads on Framed StructuresIJMER
This research work consists of a general overview of numerical analysis and dynamic
response of framed structures under impact loading. The purpose of the work is to introduce the Finite
Element Method which is difficult while analyzing dynamic response to framed structures. Also to
introduce the Ansys software and it will also explain and discuss particular model cases subjected to
various impact loadings. With these models there will be understanding of the behavior of framed
structures showing the clear results of stress, strain and deformation developed throughout the
structures.
Black Hole Detection in AODV Using Hexagonal Encryption in Manet’sIJMER
In MANETs (mobile ad hoc network), security is common problem and lack of issues in
MANET network. When comparing to wired network, MANETs are harmed to security attacks due to the
scarcity of a trusted centralized enforce authority and limited resources. This paper proposed a technique
to avoid Blackhole node behaviour in AODV (Ad Hoc On-Demand Distance Vector) using Hexagonal
Encryption inNS2. Hexagonal Encryption has been chosen for low cost and high computation speed up.
Compared to existing blackhole detection technique, this proposed technique obtains better result by
stimulating in NS2.
1. The document discusses mapping object-oriented software models to function point analysis. It proposes rules for counting function points based on the analysis phase models in the OOSE (object-oriented software engineering) methodology, including the use case model and analysis object model.
2. A tool called OOFP is proposed to measure function points from the requirements and analysis models in OOSE. The paper focuses on applying the tool and rules to the analysis phase models to identify transactional and data functions for function point counting.
3. A case study applies the proposed rules to example use case and analysis models from a course registration system to demonstrate identifying transaction and data functions for function point analysis.
Modal, Fatigue and Fracture Analysis of Wing Fuselage Lug Joint Bracket for a...IRJET Journal
This document summarizes a study on the modal, fatigue, and fracture analysis of a wing fuselage lug joint bracket for a transport aircraft. Finite element analysis was conducted in ANSYS to determine the modal frequencies and stress distributions. The first six natural frequencies were identified. Fatigue analysis using the Goodman diagram estimated the fatigue life to be 1 million cycles, qualifying it as a high cycle fatigue case. Fracture mechanics analysis identified maximum stresses near rivet holes and predicted crack initiation. The finite element analysis results for stresses, frequencies, and fatigue life were validated using analytical methods. The study aimed to understand the dynamic behavior and improve the structural integrity of the wing attachment point.
1) A prototype twisting wing was developed using shape memory alloy actuators to enable variable wing twist.
2) Benchtop and wind tunnel testing showed that the wing could be twisted up to 10 degrees using a PID controller to precisely control wing twist.
3) Wind tunnel tests measured how lift and drag coefficients varied with angle of attack for different levels of controlled wing twist.
This document summarizes the design and results of a test rig to measure lift force generated by flapping wings. Numerical modeling was used to predict lift values based on wing geometry and motion parameters like frequency and angle of attack. An experimental test rig was designed and built with servo motors in the wings to control twisting instead of relying on flexibility. Force measurements from the rig were taken using a load cell as frequency and angle of attack were varied. Results showed that increasing frequency and angle of attack both increased lift force as expected based on the numerical predictions. The document provides context on bio-inspired flight and reviews other flapping wing projects to inform the design of the test rig.
This document summarizes the structural analysis of a transport frame used to transport heavy vessels. It discusses the methodology used, which includes generating a CAD model, applying loads and boundary conditions, meshing the model, performing finite element analysis, and analyzing stress on key components like the transport frame, pins, and straps under different loading conditions like lifting and tilting. Previous studies analyzing pressure vessel support frames and compressor frames are also reviewed to understand how vibration and loads are addressed in the design of such transport structures.
This document describes a study analyzing the impact of cruise speed on the structural weight of the wings for a commercial twinjet aircraft. Ten wing designs were generated with varying cruise Mach numbers from 0.75 to 0.9 using a preliminary design tool called Asa Turbo. The wing designs were then modeled in CATIA and their structural weights estimated more accurately using a tool called PDWSW that performs preliminary wing structural design. PDWSW optimizes the wing structure layout and sizing to minimize weight while meeting strength requirements. The results provide guidance on selecting an optimal cruise speed by showing how wing structural weight evolves with speed for the aircraft concept studied.
IRJET- Finite Element Analysis of Passenger Vehicle BumperIRJET Journal
This document presents a finite element analysis of passenger vehicle bumpers to improve safety performance. The study models and simulates bumpers in LS-DYNA software to analyze deformation, impact force, stress distribution, and energy absorption using different materials and designs. Results show that modifying the bumper thickness from 3mm to 5mm significantly reduces maximum strain from 50% to 15% and decreases maximum deformation from 476mm to 423mm, improving the bumper's ability to absorb impact energy.
Computational Aerodynamic Prediction for Integration of an Advanced Reconnais...IJERA Editor
In this paper a computational aerodynamic prediction to support the aeromechanical integration of an advanced reconnaissance pod on a 5th generation fighter type aircraft is presented. The aim of the activity was to compare the aerodynamic characteristics of the new pod to a previous one already cleared on the same aircraft fleet, given verified inertial and structural similarity. Verifying the aforementioned aerodynamic similarity without involving extensive flight test activity was a must, to save time and to reduce costs. A two steps approach was required by the Certification Authority to verify, initially, the performance data compatibility in terms of aerodynamic coefficients of the old pod with the new one, in order to allow performance flight manual data interchangeability (a quantitative comparison was required); afterwards, a qualitative assessment was conducted to verify the absence of unsteadiness induced by the introduction in the external structure of the new pod of an auxiliary antenna case. Computational results are presented both for Straight and Level Un-accelerated Flight and Steady-Sideslip flight conditions at different Angles of Attack.
Modelling & Thermal analysis of pulse jet engine using CFDIRJET Journal
This document summarizes a study that used computational fluid dynamics (CFD) to analyze the combustion characteristics of a pulse jet engine. The study modeled a pulse jet engine design using CAD software and then conducted a CFD analysis using two different combustion models: an eddy dissipation model and a finite rate chemistry model. The results showed that the eddy dissipation model generated higher thrust than the finite rate chemistry model. Specifically, the eddy dissipation model produced higher exit pressures and velocities. The study concluded the proper selection of combustion model is important for accurately evaluating performance metrics like thrust generated from a pulse jet engine.
IRJET- Optimum Design of a Trailer Chassis to Overcome Failures of Welded Joi...IRJET Journal
1) The document discusses the finite element analysis of a trailer chassis to optimize its design and overcome failures in welded joints.
2) A CAD model of the chassis was created in SolidWorks and imported into ANSYS for finite element analysis to simulate loads and study stress distributions.
3) The analysis found high stresses at welded joints connecting cross members to the main frame, indicating these are failure points. Optimizing the chassis design could improve maintenance needs and reduce costs by extending the lifespan.
This document summarizes a study that analyzed the stresses in a flywheel design using finite element analysis. It describes modeling a Maruti 800 flywheel in CATIA and analyzing it in ANSYS. Two materials were considered - gray cast iron and S-glass epoxy. The flywheel was meshed and appropriate boundary conditions were applied. The results found the maximum normal stress to be 44.07 MPa for gray cast iron and 11.54 MPa for S-glass epoxy. The study demonstrated using FEA to optimize flywheel design and select suitable materials.
Strength Improvement of Bus Body Structure with Design ModificationIRJET Journal
This document summarizes research conducted to improve the strength of bus body structures through design modifications. It begins by describing issues with current bus body designs, including failures at joint locations. The objectives of the study were to analyze an existing bus body design using finite element analysis (FEA) to identify weak points, redesign problematic components like body pillars and clits to increase strength, and verify the modified design through FEA.
FEA of the original design found high stresses concentrated at clit joints, identifying them as failure prone. To address this, the researchers redesigned the clit with increased dimensions. FEA of the modified design showed reduced displacement and stresses compared to the original, confirming improved strength. The study demonstrates how
The structural analysis is an important tool that allows the research for weight reduction, the choose of the best materials and to satisfy specifications and requirements. In an aircraft’s design, several analyzes are made to prove that this aircraft will stand the set of maneuvers that it was designed to accomplish. This work will consider the preliminar project of an aircraft seeking to check the behavior of the wing under certain loading conditions in the flight envelope.To get to this load set, it has been done all the process of specification of an aircraft, such as mission definition, calculation of weight and c.g. envelope, definition of the geometric characteristics of the aircraft, the airfoil choice, preliminary performance equations, aerodynamic coefficients and the aircraft’s balancing for the equilibrium condition, but such things will not be considered in this article. For the structural analysis of the wing will be considered an arbitrary flight condition, disregarding the effect of gusts loads. With the acquisition of the items mentioned, the main forces acting on the wing structure and their equations will be calculated. The use of finite element method will enable the application of loads obtained just as the development of a method of calculation, along with the construction of a three-dimensional model that represents a chosen condition. The results will be discussed in order to explain the influence of the applied loads in the structural behavior of the wing principal structure.
This document discusses how finite element analysis can be used to optimize composite structures and reduce costs. It provides examples of how FEA was used at various stages of design, including concept design to reduce weight, detailed design to evaluate performance under different loads, laminate optimization to lower material usage, failure analysis to investigate problems, and design verification for quality assurance. One example describes how FEA optimized a helicopter axle by varying fiber orientations between bands, reducing weight from 32kg to 6kg while maintaining safety.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Development of a Model for the Simulation of ROPS Tests on Agricultural Tract...IJERA Editor
It is here proposed a methodology for simulation of ROPS tests (ROPS = Roll Over Protective Structure) of
agricultural tractor cabins. The work is based on the resolution of this problem through the use of the finite
element method. In order to limit the number of nodes of the model and thus to speed up the resolution,a twodimensional
finite elements model has been chosen. The method presented here solves with relative ease, even
very complex structures. There are also simplest methods in literature where specially made software is based
on the finite element method for simulating approval tests on ROPS structures. In this case,codes developed just
for this purposeare available, and therefore very simple to use and characterized by a high speed of preparation
of the model following the definition of a small number of parameters. On the other side these are codes
designed for structures having a specific geometric shape and in which the user is not free to set all the
parameters existing in commercial software for the structural calculation, and are not very suitable in case of
complex or not conventional structures. The methodology proposed by the authors instead, although not
automated, allows simulating any type of structure in acceptable times. The results were validated by full scale
experimental tests. Through the interpretation of the results it is possible to identify which areais the most
critical for the structure and evaluate any change, something which is not easy to do through expensive tests.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
A Brief Study, Research, Design, Analysis on Multi Section Variable Camber WingIJERA Editor
Minimizing fuel consumption is one of the major concerns in the aviation industry. In the past decade, there
have been many attempts to improve the fuel efficiency of aircraft. One of the methods proposed is to vary the
lift-to-drag ratio of the aircraft in different flight conditions. To achieve this, the wing of the airplane must be
able to change its configuration during flight, corresponding to different flight regimes.In the research presented
in this thesis, the aerodynamic characteristics of a multisection, variable camber wing were investigated. The
model used in this research had a 160mm chord and a 200mm wingspan, with the ribs divided into 4 sections.
Each section was able to rotate approximately 5 degrees without causing significant discontinuity on the wing
surface. Two pneumatic actuators located at the main spar were used to morph the wing through mechanical
linkages. The multi-section variable camber wing model could provide up to 10 percent change in camber from
the baseline configuration, which had a NACA0015 section.The wing was tested in the free-jet wind tunnel at
three different Reynolds numbers: 322000, 48000, and 636000. Static tests were performed to obtain lift and
drag data for different configurations. Two rigid wings in baseline and camber configuration were built and
tested to compare the test data with variable camber wing. The wind tunnel test results indicated that the multisection
variable camber wing provided a higher lift than the rigid wing in both configurations whereas high drag
was also generated on the variable camber wing due to friction drag on the wing skin. The larger drag value
appeared on variable camber wing in baseline configuration than in cambered configuration resulting in lower
lift-to-drag ratio as compared to the baseline rigid wing whereas the variable camber wing in cambered
configuration had higher lift-to-drag ratio than the cambered rigid wing.
Bend twist coupling effect on the Performance of the Wing of an Unmanned Aeri...IRJET Journal
This document discusses the design and analysis of a composite wing for an unmanned aerial vehicle (UAV) to minimize weight while maintaining stiffness and strength. Two wing models are created - one with all isotropic materials and one with composite materials. The composite wing is designed with glass-epoxy ribs and carbon-epoxy spars to take advantage of intrinsic bend-twist coupling effects. The wing models are analyzed in ANSYS to compare the performance of composite and isotropic materials. The results show that a composite wing can achieve lower weight without compromising structural performance.
This document describes the BMW Group's use of computational fluid dynamics (CFD) simulations in the aerodynamic development of passenger cars and motorcycles. It discusses how CFD is used at different stages of the development process to address various aerodynamic questions. It also provides details on BMW's simulation process using a Lattice-Boltzmann code, shows examples of validation cases demonstrating the achievable accuracy, and highlights practical applications of CFD including assessing aerodynamic loads, passenger comfort, and thermal management.
IRJET- Finite Element Analysis of Fuel Tank Mounting BracketIRJET Journal
1) The document describes a finite element analysis of a fuel tank mounting bracket for commercial vehicles. The goal is to optimize the design to reduce costs.
2) A baseline model of the bracket was created using Pro-E software and analyzed using Hypermesh and Optistruct. The maximum displacement was 2.7mm and stress was 20MPa.
3) A modified design with stiffeners was also analyzed. This design showed maximum displacement of 2.74mm and stress of 19.5MPa, with a 26% reduction in weight while maintaining sufficient strength over the baseline design.
Similar to Optimization of Bolted Joints for Aircraft Engine Using Genetic Algorithms (20)
A Study on Translucent Concrete Product and Its Properties by Using Optical F...IJMER
- Translucent concrete is a concrete based material with light-transferring properties,
obtained due to embedded light optical elements like Optical fibers used in concrete. Light is conducted
through the concrete from one end to the other. This results into a certain light pattern on the other
surface, depending on the fiber structure. Optical fibers transmit light so effectively that there is
virtually no loss of light conducted through the fibers. This paper deals with the modeling of such
translucent or transparent concrete blocks and panel and their usage and also the advantages it brings
in the field. The main purpose is to use sunlight as a light source to reduce the power consumption of
illumination and to use the optical fiber to sense the stress of structures and also use this concrete as an
architectural purpose of the building
Developing Cost Effective Automation for Cotton Seed DelintingIJMER
A low cost automation system for removal of lint from cottonseed is to be designed and
developed. The setup consists of stainless steel drum with stirrer in which cottonseeds having lint is mixed
with concentrated sulphuric acid. So lint will get burn. This lint free cottonseed treated with lime water to
neutralize acidic nature. After water washing this cottonseeds are used for agriculter purpose
Study & Testing Of Bio-Composite Material Based On Munja FibreIJMER
The incorporation of natural fibres such as munja fiber composites has gained
increasing applications both in many areas of Engineering and Technology. The aim of this study is to
evaluate mechanical properties such as flexural and tensile properties of reinforced epoxy composites.
This is mainly due to their applicable benefits as they are light weight and offer low cost compared to
synthetic fibre composites. Munja fibres recently have been a substitute material in many weight-critical
applications in areas such as aerospace, automotive and other high demanding industrial sectors. In
this study, natural munja fibre composites and munja/fibreglass hybrid composites were fabricated by a
combination of hand lay-up and cold-press methods. A new variety in munja fibre is the present work
the main aim of the work is to extract the neat fibre and is characterized for its flexural characteristics.
The composites are fabricated by reinforcing untreated and treated fibre and are tested for their
mechanical, properties strictly as per ASTM procedures.
Hybrid Engine (Stirling Engine + IC Engine + Electric Motor)IJMER
Hybrid engine is a combination of Stirling engine, IC engine and Electric motor. All these 3 are
connected together to a single shaft. The power source of the Stirling engine will be a Solar Panel. The aim of
this is to run the automobile using a Hybrid engine
Fabrication & Characterization of Bio Composite Materials Based On Sunnhemp F...IJMER
This document summarizes research on the fabrication and characterization of bio-composite materials using sunnhemp fibre. The document discusses how sunnhemp fibre was used to reinforce an epoxy matrix through hand lay-up methods. Various mechanical properties of the bio-composites were tested, including tensile, flexural, and impact properties. The results of the mechanical tests on the bio-composite specimens are presented. Potential applications of the sunnhemp fibre bio-composites are also suggested, such as in fall ceilings, partitions, packaging, automotive interiors, and toys.
Geochemistry and Genesis of Kammatturu Iron Ores of Devagiri Formation, Sandu...IJMER
The Greenstone belts of Karnataka are enriched in BIFs in Dharwar craton, where Iron
formations are confined to the basin shelf, clearly separated from the deeper-water iron formation that
accumulated at the basin margin and flanking the marine basin. Geochemical data procured in terms of
major, trace and REE are plotted in various diagrams to interpret the genesis of BIFs. Al2O3, Fe2O3 (T),
TiO2, CaO, and SiO2 abundances and ratios show a wide variation. Ni, Co, Zr, Sc, V, Rb, Sr, U, Th,
ΣREE, La, Ce and Eu anomalies and their binary relationships indicate that wherever the terrigenous
component has increased, the concentration of elements of felsic such as Zr and Hf has gone up. Elevated
concentrations of Ni, Co and Sc are contributed by chlorite and other components characteristic of basic
volcanic debris. The data suggest that these formations were generated by chemical and clastic
sedimentary processes on a shallow shelf. During transgression, chemical precipitation took place at the
sediment-water interface, whereas at the time of regression. Iron ore formed with sedimentary structures
and textures in Kammatturu area, in a setting where the water column was oxygenated.
Experimental Investigation on Characteristic Study of the Carbon Steel C45 in...IJMER
In this paper, the mechanical characteristics of C45 medium carbon steel are investigated
under various working conditions. The main characteristic to be studied on this paper is impact toughness
of the material with different configurations and the experiment were carried out on charpy impact testing
equipment. This study reveals the ability of the material to absorb energy up to failure for various
specimen configurations under different heat treated conditions and the corresponding results were
compared with the analysis outcome
Non linear analysis of Robot Gun Support Structure using Equivalent Dynamic A...IJMER
Robot guns are being increasingly employed in automotive manufacturing to replace
risky jobs and also to increase productivity. Using a single robot for a single operation proves to be
expensive. Hence for cost optimization, multiple guns are mounted on a single robot and multiple
operations are performed. Robot Gun structure is an efficient way in which multiple welds can be done
simultaneously. However mounting several weld guns on a single structure induces a variety of
dynamic loads, especially during movement of the robot arm as it maneuvers to reach the weld
locations. The primary idea employed in this paper, is to model those dynamic loads as equivalent G
force loads in FEA. This approach will be on the conservative side, and will be saving time and
subsequently cost efficient. The approach of the paper is towards creating a standard operating
procedure when it comes to analysis of such structures, with emphasis on deploying various technical
aspects of FEA such as Non Linear Geometry, Multipoint Constraint Contact Algorithm, Multizone
meshing .
Static Analysis of Go-Kart Chassis by Analytical and Solid Works SimulationIJMER
This paper aims to do modelling, simulation and performing the static analysis of a go
kart chassis consisting of Circular beams. Modelling, simulations and analysis are performed using 3-D
modelling software i.e. Solid Works and ANSYS according to the rulebook provided by Indian Society of
New Era Engineers (ISNEE) for National Go Kart Championship (NGKC-14).The maximum deflection is
determined by performing static analysis. Computed results are then compared to analytical calculation,
where it is found that the location of maximum deflection agrees well with theoretical approximation but
varies on magnitude aspect.
In récent year various vehicle introduced in market but due to limitation in
carbon émission and BS Séries limitd speed availability vehicle in the market and causing of
environnent pollution over few year There is need to decrease dependancy on fuel vehicle.
bicycle is to be modified for optional in the future To implement new technique using change in
pedal assembly and variable speed gearbox such as planetary gear optimise speed of vehicle
with variable speed ratio.To increase the efficiency of bicycle for confortable drive and to
reduce torque appli éd on bicycle. we introduced epicyclic gear box in which transmission done
throgh Chain Drive (i.e. Sprocket )to rear wheel with help of Epicyclical gear Box to give
number of différent Speed during driving.To reduce torque requirent in the cycle with change in
the pedal mechanism
Integration of Struts & Spring & Hibernate for Enterprise ApplicationsIJMER
This document discusses integrating the Spring, Struts, and Hibernate frameworks to develop enterprise applications. It provides an overview of each framework and their features. The Spring Framework is a lightweight, modular framework that allows for inversion of control and aspect-oriented programming. It can be used to develop any or all tiers of an application. The document proposes an architecture for an e-commerce website that integrates these three frameworks, with Spring handling the business layer, Struts the presentation layer, and Hibernate the data access layer. This modular approach allows for clear separation of concerns and reduces complexity in application development.
Microcontroller Based Automatic Sprinkler Irrigation SystemIJMER
Microcontroller based Automatic Sprinkler System is a new concept of using
intelligence power of embedded technology in the sprinkler irrigation work. Designed system replaces
the conventional manual work involved in sprinkler irrigation to automatic process. Using this system a
farmer is protected against adverse inhuman weather conditions, tedious work of changing over of
sprinkler water pipe lines & risk of accident due to high pressure in the water pipe line. Overall
sprinkler irrigation work is transformed in to a comfortableautomatic work. This system provides
flexibility & accuracy in respect of time set for the operation of a sprinkler water pipe lines. In present
work the author has designed and developed an automatic sprinkler irrigation system which is
controlled and monitored by a microcontroller interfaced with solenoid valves.
On some locally closed sets and spaces in Ideal Topological SpacesIJMER
This document introduces and studies the concept of δˆ s-locally closed sets in ideal topological spaces. Some key points:
- A subset A is δˆ s-locally closed if A can be written as the intersection of a δˆ s-open set and a δˆ s-closed set.
- Various properties of δˆ s-locally closed sets are introduced and characterized, including relationships to other concepts like generalized locally closed sets.
- It is shown that a subset A is δˆ s-locally closed if and only if A can be written as the intersection of a δˆ s-open set and the δˆ s-closure of A.
- Theore
Intrusion Detection and Forensics based on decision tree and Association rule...IJMER
This paper present an approach based on the combination of, two techniques using
decision tree and Association rule mining for Probe attack detection. This approach proves to be
better than the traditional approach of generating rules for fuzzy expert system by clustering methods.
Association rule mining for selecting the best attributes together and decision tree for identifying the
best parameters together to create the rules for fuzzy expert system. After that rules for fuzzy expert
system are generated using association rule mining and decision trees. Decision trees is generated for
dataset and to find the basic parameters for creating the membership functions of fuzzy inference
system. Membership functions are generated for the probe attack. Based on these rules we have
created the fuzzy inference system that is used as an input to neuro-fuzzy system. Fuzzy inference
system is loaded to neuro-fuzzy toolbox as an input and the final ANFIS structure is generated for
outcome of neuro-fuzzy approach. The experiments and evaluations of the proposed method were
done with NSL-KDD intrusion detection dataset. As the experimental results, the proposed approach
based on the combination of, two techniques using decision tree and Association rule mining
efficiently detected probe attacks. Experimental results shows better results for detecting intrusions as
compared to others existing methods
Natural Language Ambiguity and its Effect on Machine LearningIJMER
This document discusses natural language ambiguity and its effect on machine learning. It begins by introducing different types of ambiguity that exist in natural languages, including lexical, syntactic, semantic, discourse, and pragmatic ambiguities. It then examines how these ambiguities present challenges for computational linguistics and machine translation systems. Specifically, it notes that ambiguity is a major problem for computers in processing human language as they lack the world knowledge and context that humans use to resolve ambiguities. The document concludes by outlining the typical process of machine translation and how ambiguities can interfere with tasks like analysis, transfer, and generation of text in the target language.
Today in era of software industry there is no perfect software framework available for
analysis and software development. Currently there are enormous number of software development
process exists which can be implemented to stabilize the process of developing a software system. But no
perfect system is recognized till yet which can help software developers for opting of best software
development process. This paper present the framework of skillful system combined with Likert scale. With
the help of Likert scale we define a rule based model and delegate some mass score to every process and
develop one tool name as MuxSet which will help the software developers to select an appropriate
development process that may enhance the probability of system success.
Material Parameter and Effect of Thermal Load on Functionally Graded CylindersIJMER
The present study investigates the creep in a thick-walled composite cylinders made
up of aluminum/aluminum alloy matrix and reinforced with silicon carbide particles. The distribution
of SiCp is assumed to be either uniform or decreasing linearly from the inner to the outer radius of
the cylinder. The creep behavior of the cylinder has been described by threshold stress based creep
law with a stress exponent of 5. The composite cylinders are subjected to internal pressure which is
applied gradually and steady state condition of stress is assumed. The creep parameters required to
be used in creep law, are extracted by conducting regression analysis on the available experimental
results. The mathematical models have been developed to describe steady state creep in the composite
cylinder by using von-Mises criterion. Regression analysis is used to obtain the creep parameters
required in the study. The basic equilibrium equation of the cylinder and other constitutive equations
have been solved to obtain creep stresses in the cylinder. The effect of varying particle size, particle
content and temperature on the stresses in the composite cylinder has been analyzed. The study
revealed that the stress distributions in the cylinder do not vary significantly for various combinations
of particle size, particle content and operating temperature except for slight variation observed for
varying particle content. Functionally Graded Materials (FGMs) emerged and led to the development
of superior heat resistant materials.
Energy Audit is the systematic process for finding out the energy conservation
opportunities in industrial processes. The project carried out studies on various energy conservation
measures application in areas like lighting, motors, compressors, transformer, ventilation system etc.
In this investigation, studied the technical aspects of the various measures along with its cost benefit
analysis.
Investigation found that major areas of energy conservation are-
1. Energy efficient lighting schemes.
2. Use of electronic ballast instead of copper ballast.
3. Use of wind ventilators for ventilation.
4. Use of VFD for compressor.
5. Transparent roofing sheets to reduce energy consumption.
So Energy Audit is the only perfect & analyzed way of meeting the Industrial Energy Conservation.
An Implementation of I2C Slave Interface using Verilog HDLIJMER
This document describes the implementation of an I2C slave interface using Verilog HDL. It introduces the I2C protocol which uses only two bidirectional lines (SDA and SCL) for communication. The document discusses the I2C protocol specifications including start/stop conditions, addressing, read/write operations, and acknowledgements. It then provides details on designing an I2C slave module in Verilog that responds to commands from an I2C master and allows synchronization through clock stretching. The module is simulated in ModelSim and synthesized in Xilinx. Simulation waveforms demonstrate successful read and write operations to the slave device.
Discrete Model of Two Predators competing for One PreyIJMER
This paper investigates the dynamical behavior of a discrete model of one prey two
predator systems. The equilibrium points and their stability are analyzed. Time series plots are obtained
for different sets of parameter values. Also bifurcation diagrams are plotted to show dynamical behavior
of the system in selected range of growth parameter
CHINA’S GEO-ECONOMIC OUTREACH IN CENTRAL ASIAN COUNTRIES AND FUTURE PROSPECTjpsjournal1
The rivalry between prominent international actors for dominance over Central Asia's hydrocarbon
reserves and the ancient silk trade route, along with China's diplomatic endeavours in the area, has been
referred to as the "New Great Game." This research centres on the power struggle, considering
geopolitical, geostrategic, and geoeconomic variables. Topics including trade, political hegemony, oil
politics, and conventional and nontraditional security are all explored and explained by the researcher.
Using Mackinder's Heartland, Spykman Rimland, and Hegemonic Stability theories, examines China's role
in Central Asia. This study adheres to the empirical epistemological method and has taken care of
objectivity. This study analyze primary and secondary research documents critically to elaborate role of
china’s geo economic outreach in central Asian countries and its future prospect. China is thriving in trade,
pipeline politics, and winning states, according to this study, thanks to important instruments like the
Shanghai Cooperation Organisation and the Belt and Road Economic Initiative. According to this study,
China is seeing significant success in commerce, pipeline politics, and gaining influence on other
governments. This success may be attributed to the effective utilisation of key tools such as the Shanghai
Cooperation Organisation and the Belt and Road Economic Initiative.
Optimizing Gradle Builds - Gradle DPE Tour Berlin 2024Sinan KOZAK
Sinan from the Delivery Hero mobile infrastructure engineering team shares a deep dive into performance acceleration with Gradle build cache optimizations. Sinan shares their journey into solving complex build-cache problems that affect Gradle builds. By understanding the challenges and solutions found in our journey, we aim to demonstrate the possibilities for faster builds. The case study reveals how overlapping outputs and cache misconfigurations led to significant increases in build times, especially as the project scaled up with numerous modules using Paparazzi tests. The journey from diagnosing to defeating cache issues offers invaluable lessons on maintaining cache integrity without sacrificing functionality.
Embedded machine learning-based road conditions and driving behavior monitoringIJECEIAES
Car accident rates have increased in recent years, resulting in losses in human lives, properties, and other financial costs. An embedded machine learning-based system is developed to address this critical issue. The system can monitor road conditions, detect driving patterns, and identify aggressive driving behaviors. The system is based on neural networks trained on a comprehensive dataset of driving events, driving styles, and road conditions. The system effectively detects potential risks and helps mitigate the frequency and impact of accidents. The primary goal is to ensure the safety of drivers and vehicles. Collecting data involved gathering information on three key road events: normal street and normal drive, speed bumps, circular yellow speed bumps, and three aggressive driving actions: sudden start, sudden stop, and sudden entry. The gathered data is processed and analyzed using a machine learning system designed for limited power and memory devices. The developed system resulted in 91.9% accuracy, 93.6% precision, and 92% recall. The achieved inference time on an Arduino Nano 33 BLE Sense with a 32-bit CPU running at 64 MHz is 34 ms and requires 2.6 kB peak RAM and 139.9 kB program flash memory, making it suitable for resource-constrained embedded systems.
artificial intelligence and data science contents.pptxGauravCar
What is artificial intelligence? Artificial intelligence is the ability of a computer or computer-controlled robot to perform tasks that are commonly associated with the intellectual processes characteristic of humans, such as the ability to reason.
› ...
Artificial intelligence (AI) | Definitio
Discover the latest insights on Data Driven Maintenance with our comprehensive webinar presentation. Learn about traditional maintenance challenges, the right approach to utilizing data, and the benefits of adopting a Data Driven Maintenance strategy. Explore real-world examples, industry best practices, and innovative solutions like FMECA and the D3M model. This presentation, led by expert Jules Oudmans, is essential for asset owners looking to optimize their maintenance processes and leverage digital technologies for improved efficiency and performance. Download now to stay ahead in the evolving maintenance landscape.
Introduction- e - waste – definition - sources of e-waste– hazardous substances in e-waste - effects of e-waste on environment and human health- need for e-waste management– e-waste handling rules - waste minimization techniques for managing e-waste – recycling of e-waste - disposal treatment methods of e- waste – mechanism of extraction of precious metal from leaching solution-global Scenario of E-waste – E-waste in India- case studies.
Optimization of Bolted Joints for Aircraft Engine Using Genetic Algorithms
1. International
OPEN ACCESS Journal
Of Modern Engineering Research (IJMER)
| IJMER | ISSN: 2249–6645 | www.ijmer.com | Vol. 4 | Iss. 5| May. 2014 | 76 |
Optimization of Bolted Joints for Aircraft Engine Using Genetic
Algorithms
Juan Carlos Barbosa M.Eng.1
, Saúl D. Santillán Gutierrez, PhD 2
, Fernando
Velázquez Villegas, PhD3
.
1
(Core Engineering, Bombardier Aerospace, Canada)
2
(High Technology Center, National Autonomous University of Mexico, Mexico)
3
(Mechanical Design and Technological Innovation Center, National Autonomous University of Mexico,
Mexico)
I. INTRODUCTION
The requirements for the design of components in the aerospace industry are considerably larger and
more restrictive compared to other industries because their failure could result in accidents with a high
fatality’s ratio. Examples of these components are the axial bolted joints whose failure could result in the
complete separation of sections for an aircraft engine.
To guarantee the airworthiness of these components, the regulation agencies such as the Federal
Aviation Administration (FAA) or the European Aviation Safety Agency (EASA), require series of
requirements to demonstrate the security of the elements [Ref. 1]. Among others, the parts must demonstrate
structural positive margins of safety for:
• No deformation under limit loads (maximum load in service)
• No rupture under ultimate loads (loads covering an unexpected event, such as landing with failed landing
gear)
• Damage tolerant parts
• Cyclic Fatigue
In order to accomplish all the requirements and get the airworthiness certification, the aircraft usually
follows the design process described below:
Phase 1 Conceptual Design: Definition of basic functions of the product based in customer requirements.
Phase 2: Preliminary Design: Models and analyses are performed for the chosen conceptual design. Through
analysis and experience on previous similar products, the first structural calculations are carried out and
compared to requirements.
Phase 3: Detailed Design: Based in results from the Preliminary Design, the design is refined and optimized.
The final design is tested and certified.
Abstract: Genetic Algorithms mimic the evolving technique of nature to better fit populations to a
certain environment. Despite this technique has proved its adequacy in several fields, its application in
Aerospace is still limited, mostly because of the high quantity of acceptability criteria that the design
must pass and the amount of design parameters. The presented paper explores required GA
architecture’s adaptations to be applied in highly restricted systems such as those commonly found in
Aerospace applications. The proposed GA was applied to the design of an Aircraft Engine’s Axial Casing
bolted joint following static strength restrictions as per FAR 33 regulations. The set of Elitism,
interdependent geometric restrictions, Crossing, and Reproduction modules proved the applicability of
the presented multi-objective GA architecture under 14 restrictions for normal, limit and ultimate loads.
As it is described, the conversion is quickly achieved due to the shortage of the search space; therefore a
modified Variable Crossing per Scheme is proposed to expand the diversity of the genome to compensate
the relatively low impact of the Mutation module. Finally, the process and solutions found were
compared against the traditional design process, showing the feasibility of this technique in complex
applications in terms of quality of the solution and developing time.
Keyword: Aircraft Engine, Bolted Joints, Genetic Algorithms, Optimization.
2. Optimization of Bolted Joints for Aircraft Engine using Genetic Algorithms
| IJMER | ISSN: 2249–6645 | www.ijmer.com | Vol. 4 | Iss. 5| May. 2014 | 77 |
Due to the complexity of the system and the multiples interactions between design’s groups working
on the simultaneous design of different components of the turbine, the optimization is only carried out at the
latest part of the detailed design phase, thus most of the optimization range is narrowed due to its impact to
adjacent systems and lack of time. Proof of that are the several cost and weight reduction projects and
redesigns throughout the life of the product.
Despite the proved capability of evolving computational techniques, such as the genetic algorithms,
there are just few applications reported for the aerospace industry [Ref. 2]. It can be highlighted the works of
Xie et all [Ref. 3] for the optimization of an aircraft wing and Ali et all and Marta [Ref. 4 and Ref. 5] for the
conceptual design of an aircraft.
The objective of this research was to evaluate the application of evolving computational techniques in
the design and optimization of a structural element for the aerospace industry that could be applied to early
phases of the design, and to evaluate in quality and time the results compared to the traditional method. Based
on its complexity, the design of an axial bolted joint for an aircraft engine provides a good case of study for a
real application.
Figure 1. GE J85 Jet Engine External Bolted Joints
In this research, the following contributions are made:
• A novel architecture of an evolving computational technique using Genetic Algorithms (GA) is presented
focused to solve the problem of a high restricted system of solutions using populations of tailor made
genome performing under several restrictions and highly constrained acceptance criteria. The structure is
composed of elitism functions, variable cross reproduction and selective functions for the reproductions.
• The structure of the GA was evaluated for designing a part where there is extensive work performed in
order to optimize it with traditional methods: an axial bolted joint for an aircraft engine, being this a
novel application of the GA’s in a specific Aerospace design problem.
II. BOLTED JOINT CALCULATION
As previously stated, a bolted joint in general, and particularly those joining the multiple casings
along the aircraft engine, has several design restrictions. Some of these restrictions are the ones guaranteeing
the design strength under different load events such as Normal Loads (loads expected to happen every flight),
Limit Loads (maximum loads to be expected in service) or Ultimate Load (limit loads multiplied by a
prescribed factor of safety, used for non-expected in service events). From the Federal Aviation Regulation,
paragraph 33.24 [Ref. 1], the following set of requirements is imposed in order to have a valid design:
Requirements under Normal Operation Loads
1. More than 20% Margin of Safety (MoS) for net tension stress on the bolt against average yield strength
with average preload.
2. Positive MoS for concentrated stresses on threads and on head’s fillet against minimum yield strength
with average preload.
3. Positive MoS for crush stress against minimum yield strength with average preload.
4. Positive MoS for flange bending stress against minimum yield strength.
3. Optimization of Bolted Joints for Aircraft Engine using Genetic Algorithms
| IJMER | ISSN: 2249–6645 | www.ijmer.com | Vol. 4 | Iss. 5| May. 2014 | 78 |
5. More than 20% Separation Margin with minimum preload.
6. More than 20% Anti-rotational Margin with minimum preload.
Requirements under Limit Loads
7. Positive MoS for net tension stress on the bolt against average yield strength with average preload.
8. Positive MoS for concentrated stress less than average yield strength with average preload
9. Positive MoS for crush stress against average yield strength with average preload.
10. Positive MoS for flange bending stress against average yield strength.
11. Positive Separation Margin with average preload.
12. Positive Antirotational Margin with average preload.
Requirements under Ultimate Loads
13. Positive MoS for net tension stress on the bolt against minimum ultimate strength with average preload.
14. Positive MoS for flange bending stress against minimum ultimate strength.
Figure 2. Summary of Bolted Joint Requirements
In order to calculate the margin of safety associated to each requirement, it is required to evaluate the
load components acting on each casing’s flange. The loads on a flanged cylindrical bolted joint such as those
used in an aircraft engine come from several sources. Internal pressure, thrust, vibration, temperature
gradients, and torque are only examples of these load excitations. The loads considered for the study case can
be divided in Axisymmetric and Asymmetric loads as described in Fig. 3.
Figure 3. Bolted Joint Loads
4. Optimization of Bolted Joints for Aircraft Engine using Genetic Algorithms
| IJMER | ISSN: 2249–6645 | www.ijmer.com | Vol. 4 | Iss. 5| May. 2014 | 79 |
The analysis described in this paper corresponds to a bolted joint with Normal, Limit and Ultimate
loads of an aircraft engine in the order of ~30,000 lbs of thrust; however the methodology can be extrapolated
to other thrust levels.
Once that the asymmetric and symmetric loads are translated into an axial, radial force and a bending
moment for each segment defined by the pitch of the bolt (Fig. 4), each of them were analyzed as an eccentric
prying joint following the procedure defined by Bickford (Ref. 6). This process has to be repeated for each set
of loads (normal, limit, ultimate), for each bolted joint segment (number of bolts in the design) and each design
proposal. Due to the nature of the iterative process, it is proposed the use of a Genetic Algorithm to find an
optimal solution that minimizes the weight under the several design restrictions.
Figure 4. Segment of a Bolted Joint
III. GENETIC ALGORITHM
Background:
The GA’s were developed by John Holland in the 1960s as an abstraction of biological evolution and
gave a theoretical framework for adaptation under the GA. But it was not until the development of computers
where this field showed its potential [Ref. 7].
The basic architecture of a GA (Fig. 5) consists in a population of individuals whom genetic
information consists in chromosomes mathematically modeled as bits (0, 1). A group of chromosomes create a
scheme which represents a design characteristic in the model (such as a variable design’s dimension). Once
that an initial population is created, each individual is evaluated using a fitness function and according to its
performance, a score is assigned related to the optimization goal. The best suited individuals are picked for
crossover and generate children individuals forming the next generation. Since only the best individuals were
selected for defining the next generation, as evolution in nature, the population would improve generation by
generation.
Figure 5. Basic GA Architecture
GA Modeling:
For the presented case of study, it was assumed that the diameters and thicknesses of the casings to
join were already defined by the designer and those are considered inputs for the GA (Fig. 6). The flanges and
bolted joint elements, such as bolts, nuts, washers, and the required torque to join them are modeled in the GA
through 9 schemas:
1. Bolt & Nut type
2. Bolt & Nut Quantity equally spaced.
3. Bolt & Nut Material
4. Left Flange Thickness
5. Right Flange Thickness
Initial Population
Start
Fitness Evaluation
Crossover
New Generation
Convergence?
Mutation
End
5. Optimization of Bolted Joints for Aircraft Engine using Genetic Algorithms
| IJMER | ISSN: 2249–6645 | www.ijmer.com | Vol. 4 | Iss. 5| May. 2014 | 80 |
6. Washer Quantity &Thickness
7. Torque applied to the bolt
8. External diameter of flanges and Radius of action of the Bolted Joint
9. Radii of flange and case union
Figure 6. Inputs and Elements Optimized in a Bolted Joint
In order to guarantee a wide range of potential solutions, the system was modeled with 22 genes that create a
search space of 4.2x106
combinations:
Table 1. Genome of Each Individual Representing a Design
Genes Combinations Characteristic
2 4 Bolt Type
1 2 Bolt Material
4 16 Bolt Quantity
3 8 External Flange Diameter
2 4 Radii
3 8 Left Flange Thickness
3 8 Right Flange Thickness
2 4 Washers
2 4 Torque
To avoid having individuals with non-functional designs, such as a design having a diameter of the
flange’s bolt hole larger than the bolthead diameter, some features are defined as a function of the Individual’s
gens. For example, the search space for the external flange diameter consisted in 8 combination between 1 to 3
times the bolthole radius, and this last was defined as the diameter of the bolt plus a fixed clearance. This
guarantees that the 4.2x106
combinations represent in fact valid designs from the geometrical point of view.
Elitist Function:
The GA uses an elitist function that forces the algorithm to work with only valid individuals; this
means that any geometrically valid design have to pass the 14 design requirements previously to be part of the
population.
This rule was followed not only for the creation of the first generation’s population, but also after a
new individual was created after the crossing and reproduction. While this created a highly restricted system, it
helped to work exclusively with valid designs, speeding up the process and emulating what should have been
done in the Preliminary and Detailed Design Phases of the traditional design methodology.
Crossing:
As a first option, it was considered the most frequent crossing method, which consists in the wheel
roulette for defining a crossing point in the genome of the parents, and mixing the gametes to create two
descendents as shown in Fig. 7. [Ref. 8, Ref. 9].
TL TR
lo
liRiL RiR
Lxl Lxr
Rl
Rb
Dh
TArmL TArmR
WOD
WID
DS
DHB
DHN
WT
Inputs
Variables to be Optimized
6. Optimization of Bolted Joints for Aircraft Engine using Genetic Algorithms
| IJMER | ISSN: 2249–6645 | www.ijmer.com | Vol. 4 | Iss. 5| May. 2014 | 81 |
Figure 7. Random Unique Crossing
As specified before, the design was modeled using 9 schemes or groups of genes defining the physical
characteristics of the bolted joint (Fig. 8). Since this method has a unique cross point, 10 of the 23 (43%)
potential cross points are actually boundary of the schemes, thus there are 43% that the individuals created
with this technique would have the same scheme as one of their parents. As it will be shown later, this has an
impact on the converging time and the possibility of getting stuck on local optima.
Figure 8. Random Unique Crossing Points
Opposite than the single point genetic algorithm and other methods (Ref. 10), a second option of a
variable crossing per each scheme was developed. This consists in randomly picking a crossing point for each
scheme that represents a physical characteristic, such as the bolt quantity (Fig. 9). This crossing generates non-
continuous gametes from the parents, then having creating a larger genome pool for the population.
Figure 9. Variable Crossing per Scheme
00
Bolt Type
0 0000 000 00 000 000 00 00
Bolt Material
Bolt Quantity
Flange’s External Ligament
Radii
Left Flange Thickness
Right Flange Thickness
Washer Thickness
Torque
11 1 1111 111 11 111 111 11 11
0 2 7 10 12 15 18 20 22Cross Point
Parent 1
Parent 2
3
01 0 0011 101 10 100 110 01 11 11 0 1111 000 11 100 111 01 01
Parent 1
Gamete 1+ Gamete 4
0* * 001* 1** 10 1** *** 0* 1*
*1 0 ***1 *01 ** *00 110 *1 *1
1* * 111* 0** 11 1** *** 0* 0*
*1 0 ***1 *00 ** *00 111 *1 *1
01 0 0011 100 10 100 111 01 11 11 0 1111 001 11 100 110 01 01
Parent 2
Gamete 1 Gamete 3
Gamete 2 Gamete 4
Crossing Points Crossing Points
Descendent 1 Descendent 2
Gamete 2+ Gamete 2
7. Optimization of Bolted Joints for Aircraft Engine using Genetic Algorithms
| IJMER | ISSN: 2249–6645 | www.ijmer.com | Vol. 4 | Iss. 5| May. 2014 | 82 |
Since there are 9 crossing points for each individual, the descendents would preserve parents´
characteristics defined characteristic and searching faster for improving combinations of those characteristics.
This option maximizes the diversity of the population in highly restricted systems. The difference between
these two methods can be easier visualized through an example. If the scheme defining the genome of bolt
quantity of one parent represents 50 bolts and the for the other parent 30 bolts, the unique crossing point will
most likely generate individuals with either 50 or 30 bolts, since the probability of having the unique crossing
in the bolt quantity scheme is only 3/23. The Variable Crossing per Scheme will break the gene’s sequence in
order to find intermediate values as well.
Reproduction:
Most of the existing GA methods present a system of reproduction where a couple of parents create a
couple of descendents as shown in Fig. 7 and Fig. 9. This process guarantees to have continuity in the
population size throughout the generation. For the presented case of study, this method did not perform very
well. Since the system is over-restricted due to the high quantity of design requirements, the possibility of
finding two valid parents that could create two valid descendents was very low, and when this happened, it was
because the parents’ genomes were so similar, that the created descendents had a very small improvement in
performance, moreover they were almost identical. In order to guarantee that a couple of parents, not sharing a
similar genome, could generate valid descendents, it was decided to select only one individual from those
generated for the crossover, using the child with better performance. It was also decided that if after 20
attempts a valid individual was not generated, to replace the child with the best performing parent for the next
population through a tournament selection. To guarantee the dimension of the population, this process was
repeated until the new generation had the same dimension as its precedent.
Mutation:
Different rates of Mutation were imposed to the algorithm between 1% to 3%, however no significant
impact was recorded in the results. Most likely, the null effect of mutation comes from the fact that, due to the
high constrained system, the probability of creating a valid individual was too low and the elitism criteria
rejected the potential mutation.
Convergence:
The convergence criteria used in the algorithm was through the number of generations without a
change of added volume (as all the materials in the design where Inconel 718) for the best evaluated individual
of the population. This number was increased from 3 to 10, however after 5 no significant changes were
recorded.
IV. RESULTS
Although the elitism helped to converge in terms of number of generations, it took a great amount of
iterations just to have a valid initial population. As shown in the Fig 10-a, only in less than 10% of the cases it
was required one iteration to create a valid individual. In average it took ~17 iterations to get a valid design.
Additionally, the elitism had an impact in the computational time for the GA. From several experiments, it
was measured that approximately 20% of the GA computational time was consumed by producing valid
individuals for the initial population.
Figure 10. Evaluation of GA Parameters
8. Optimization of Bolted Joints for Aircraft Engine using Genetic Algorithms
| IJMER | ISSN: 2249–6645 | www.ijmer.com | Vol. 4 | Iss. 5| May. 2014 | 83 |
Since the convergence is achieved very fast (usually in less than 20 iterations), it is very important to
have a relatively large population to guarantee that a wide spectrum of design characteristics are represented.
In order to evaluate the quantity of individual required in the population to have reliable results, the GA was
run 200 times with populations of 25 to 125 individuals. The analysis was repeated for the two crossing
techniques explained above. Comparing the results of Figure 10.b, it can be noted that after 100 individuals in
the population, there is no a substantial improvement in the results, thus 100 individuals can be considered as
appropriate for the analyzed problem. Additionally, it can be seen a clear positive offset of the variable crossing
per scheme technique over the random unique crossing. This can be explained by the fact that the variable
crossing per scheme technique adds diversity to the population by expanding the search area to new proposals
and in this over-constrained system, the diversity avoids being stuck in local optima.
Fig 11 show the general behavior of results of the volume added in average per generation and the
volume added by the best individual in the generation. Fig 12 shows graphically the evolution of the design
characteristics.
Figure 11. Average Added Volume and Volume for Best Individual per Generation
Figure 12. Evolution per Generation for Average Population and Best Individual
9. Optimization of Bolted Joints for Aircraft Engine using Genetic Algorithms
| IJMER | ISSN: 2249–6645 | www.ijmer.com | Vol. 4 | Iss. 5| May. 2014 | 84 |
Before analyzing the study case with the GA tool, it was traditionally analyzed by a designer using a
spreadsheet containing the evaluation function (Margins of Safety to the 14 design requirements). After
approximately 5 hours it was possible to find the first acceptable design. It was needed approximately 3 more
hours to find an optimal solution that added 58in3
of volume. Despite the fact that the comparison was
performed with only one case, the result is contrasting. In average, the solution using the GA takes 15 minutes
for a population of 100 individuals and the volume added is approximately 19.4in3
.
V. CONCLUSION
The current situation of the aerospace industry, with fuel economy as prime criteria for improving
aircraft and engines, combined with higher costs of production and more exotic and costly materials, requires
novel optimization techniques that could be applied in the early design phases. Although there had been
several evolutionary computing techniques evolving computational techniques reported in the literature, the
application of these tools are still limited to experimental systems, despite their potential for improving designs
faster than traditional design methods. As shown in this research, the single point crossover GA technique
does not work very well, because the highly constrained nature of the problem. On the other hand, once the
populate generation was solved, the alternative crossover proposed in the research led to fast results and with
positive potential, both in time and technical parameters, compared with traditional design processes.
However, the GA based proposed system, requires a lot of knowledge from the designer in order to
define the initial constraints for the problem to be solved. Whereas the engineering judgment is very important,
the research showed promising results with better technical parameters, weight reduction and shorter
developing time. Despite the promising results of this research showing the potential of using evolutionary
optimization techniques for the aerospace industry, still a lot of work is required in order to meet the
regulations for such specialized industry. It is also important to note that the GA’s do not work completely
independently since the engineering judgment is critical to define the boundaries of each explored design
parameter, and if the range does not include the global optima, simply the GA will not find it.
This roadblock can be avoided by using the GA’s in steps, starting with an obviously large range for
each design parameter, and then narrowing the range in the following runs.It is intended to explore further
applications of these techniques increasing the number of design requirements that were ignored in this first
approach such as thermal loads, damage tolerance, buckling, low cycle and high fatigue. Additionally, other
systems and design problems will be explored such as the design of flanges, stringers, panels or the shape of an
aircraft window.
REFERENCES
[1] Code of Federal Regulations - Title 14 Aeronautics and Space – Part 33 Airworthiness Standards: Aircraft Engines
(Federal Aviation Administration, 2012).
[2] M. B. Anderson, Genetic Algorithms in Aerospace Design, Substantial Progress, Tremendous Potential, RTO-EN-
022 NATO, 2003.
[3] A. Lencus, O. Querin, G. Steven and Y.M. Xie, Aircraft Wing Design Automation with ESO and GESO,
International Journal of Vehicle Design, 28(3), 2001.
[4] N. Ali, K. Behdinan, Conceptual Aircraft Design – A Genetic Search and Optimization Approach, International
Council of the Aeronautical Sciences, Congress, 2002.
[5] A. C. Marta, Parametric Study of a Genetic Algorithm using an Aircraft Design Optimization Problem, Standford
University, Department of Aeronautics and Astronautics, 2003.
[6] J. H. Bickford, An Introduction to the Design and Behavior of Bolted Joints (Taylor & Francis Group Press, 1995).
[7] M. Mitchell, An Introduction to Genetic Algorithms, (The MIT Press, 1998).
[8] D.E. Goldberg, Genetic Algorithms in Search, Optimization, and Machine Learning, (Addison-Wesley Press,
1989).
[9] J. R. Koza , Genetic Algorithms, (Elsevier Science Press, 1993).
[10] L. Davis, Handbook of Genetic Algorithms, (VNR Press, 1991).