This work aims to develop a methodology for numerical evaluation via finite elements applied to projects shields sheet metal. To validate the methodology physical test were conduct and were compare with the numerical simulation. In the simulation, a plasticity material modelit was used at high strain rates, besides the insertion of a damage model through forming limit diagram (FLD) to capture the initiation of damage and energy criteria for propagation of the fracture. The tested shielding design is for the II-A protection level using the type 9mm ammunition.
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.
Forming Limit Prediction of High Tensile Strength Steel using FEA SimulationIJERD Editor
Forming limit prediction of High Tensile Strength Steel (HTSS) sheet was carried out by using finite element analysis. JSTAMP/NV was used in the finite element analysis. Thickness of HTSS specimen was 1.0mm, and the length was 120mm.And the width was varied from 20mm to 80mm. Stretching test was operated by Erichsen test. In this study, the forming limit prediction method for predicting the localized necking before the fracture was proposed.FLD of HTSS was compared between experimental results and analytical results. Forming limit diagrams (FLD) obtained by FEAagreed well with the FLD obtained by experiment.
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.
Evaluation of Damage by the Reliability of the Traction Test on Polymer Test ...inventy
In recent decades, polymers have undergone a remarkable historical development and their use has been greatly imposed by gradually dethroning most of the secular materials. These polymer materials have always distinguished themselves by their simple shaping and inexpensive price, their versatility, lightness, and chemical stability but despite their massive use in everyday life as well as in advanced technologies. Generally, these materials still not understood which requires a thorough knowledge of their chemical, physical, rheological and mechanical properties. This paper, we study the mechanical behavior of an amorphous polymer: Acrylonitrile Butadiene Styrene “ABS” by means of uniaxial tensile testing on pierced test pieces with different notch lengths ranging between 1 to 14mm.The proposed approach consists in analyzing the evolution of the global geometry of the obtained strain curves by taking into account the zones and characteristic points of these curves as well as the effect of the damage on the mechanical behavior of the polymer ABS, in order to visualize the evolution of the damage by a static model
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.
Forming Limit Prediction of High Tensile Strength Steel using FEA SimulationIJERD Editor
Forming limit prediction of High Tensile Strength Steel (HTSS) sheet was carried out by using finite element analysis. JSTAMP/NV was used in the finite element analysis. Thickness of HTSS specimen was 1.0mm, and the length was 120mm.And the width was varied from 20mm to 80mm. Stretching test was operated by Erichsen test. In this study, the forming limit prediction method for predicting the localized necking before the fracture was proposed.FLD of HTSS was compared between experimental results and analytical results. Forming limit diagrams (FLD) obtained by FEAagreed well with the FLD obtained by experiment.
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.
Evaluation of Damage by the Reliability of the Traction Test on Polymer Test ...inventy
In recent decades, polymers have undergone a remarkable historical development and their use has been greatly imposed by gradually dethroning most of the secular materials. These polymer materials have always distinguished themselves by their simple shaping and inexpensive price, their versatility, lightness, and chemical stability but despite their massive use in everyday life as well as in advanced technologies. Generally, these materials still not understood which requires a thorough knowledge of their chemical, physical, rheological and mechanical properties. This paper, we study the mechanical behavior of an amorphous polymer: Acrylonitrile Butadiene Styrene “ABS” by means of uniaxial tensile testing on pierced test pieces with different notch lengths ranging between 1 to 14mm.The proposed approach consists in analyzing the evolution of the global geometry of the obtained strain curves by taking into account the zones and characteristic points of these curves as well as the effect of the damage on the mechanical behavior of the polymer ABS, in order to visualize the evolution of the damage by a static model
An Experimental Investigation into the Grindability Aspects of Newly Develope...IDES Editor
Ceramics are getting widely used in many engineering applications. These ceramic materials need to be ground. Unfortunately, the ground ceramic components mostly contain surface/subsurface damages. To minimize the grinding induced damages selection of appropriate grinding process parameters is very important. Ceramic composite material (AlSiTi) has been selected in the present study to investigate its grindability. This research work deals with the analysis of the process parameters such as wheel speed, table feed and infeed as influential factors, on the force components, grinding specific energy and surface roughness values based
on Taguchi’s experimental design method. Scanning electron microscopy (SEM) has been used to analyze the subsurface damages. The result provides valuable insight into the grindability aspects of the composite ceramic (AlSiTi).
Static Analysis of Single Lap Joint of Composite Materialsijsrd.com
Mechanically fastened joints are critical parts in composite aircraft structures. The composite structural members are highly used in the following applications such as aerospace, automobiles, marine, architecture etc., In the past decades, adhesive bonding is a practical joint method for joining composite materials which provide low shear and tensile strength .To improve the tensile strength, the joint is made with material joint. Glass Fiber/Chopped strands mat and Bi-Directional fly / Epoxy composite is fabricated by hand lay-up method. The tensile properties of the material joint are obtained and compared with that of bolted joint. The experimental results shows that the material joint has superior tensile properties than the bolted joint and the Bi-Directional fly composite exhibits superior tensile strength than the chopped strands mat. Finite element analysis also done and compared with the experimental results and found to be similar.
Size effect of plain concrete beams–an experimental studyeSAT Journals
Abstract
The paper analyses the size dependency of the fracture energy (GF) and the effective length of fracture process zone (Cf) of concrete
determined as per the Bazant’s Size effect method and RILEM Work-of-fracture methods. The fracture parameters (GF,Cf) are
determined by measuring the maximum loads of geometrically similar notched plain concrete (M25) specimens of different sizes in a
size ratio of 1:5 with different pre-cast notch depths (a/d=0.15, 0.30 and 0.45) under three point bending through load-deflection
curves. In each notch depth ratio, 15 beams are cast and tested with 03 similar specimens in each size of the beams. Total beams
tested are 45.The variation of both the fracture energy and the effective length of fracture process zone as a function of the specimen
size and notch depth is determined using Bazant’s Size effect method and RILEM Work-of-fracture method. Fracture energy and
Fracture process zone length determined by Size effect method are found to be decreasing with the increasing notch depth ratios.
Fracture energy calculated using Work-of-fracture method is increasing with the increase in size of specimen and decreasing with the
increasing notch depth ratios.
Vibrational Analysis Of Cracked Rod Having Circumferential Crack IDES Editor
The frequency ratio of torsional vibration of a rod without crack and of rod with crack subjected to torque at the free end for various crack depth and varying crack location is investigated. It is found that even a cracked of small depth is
dangerous at the fixed end, also as the crack depth is increases more than 50% of diameter of rod there is a considerable drop in natural frequency of the rod .
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 paper addresses the fracture toughness ( ), or also known as critical stress intensity Factor, according to
conditions of Lineal Elastic Fracture Mechanics (LEFM). The characterization of the mechanical properties in
tensile and fracture toughness of structural steel pipes API-5L used in hydrocarbons transportation was
performed. For fracture toughness, the material was tested through fatigue crack propagation on standardized
compact specimen (CT) according to ASTM E-399 norm. A thickness (B) equal to and a crack size (a) equal
to 0.5w were used. With the porpoise of establishing the adequate conditions at the crack tip, the specimens were
subjected to fatigue pre-cracking by application of repeated cycles of load in tensile-tensile and constant load
amplitude with a load ratio of R = 0.1. The experimental Compliance method was used based on data obtained
from load vs. Crack Mouth Opening Displacement (CMOD). The results show a Stress Intensity factor of 35.88
MPa√m for a 25 mm crack size specimen. The device used for testing is a MTS-810 machine with capacity of
100KN and 6 kHz sampling rate, which meets the conditions of the ASTM E-399 standard. The cracking
susceptibility of steel is influenced by the size, morphology and distribution of non-metallic inclusions,
thermochemical interaction with the environment and microstructure.
Finite Element Analysis of the Composite Patch Repairs of the PlatesIJERA Editor
Adhesively-bonded patches are used for repair of different types of damages such as holes, notches, scratches, cracks etc. occurring in metallic as well as composite structures. The composite patching is the most widely used method of restoring the load-carrying capacity of the weakened structure. Due to the rapid growth of aerospace industry, analysis of adhesively-bonded patches to repair cracked structures have been the focus for many years. Most of these studies investigated repaired structures using linear analysis and demonstrated the viability of adhesively-bonded patch-repairs as a means to improve the durability and damage tolerance of cracked metallic structures efficiently and economically.Many researchers performed more intensive research on the method and presented the advantages of a composite material patch used for the cracked plate repairing. It was found that the bonded patch method not only reduces the weight but also increases the service life.In this research work, the analysis of cracked metallic and composite plates which are repaired by bonded-composite patches is performed using Finite Element Analysis package FRANC2D/L. This package is available with its corresponding mesh generating program CACSA. They are developed by Cornel Fracture Group, Cornel University.In this study, various fracture parameters for the structures are found out. It revealed that, the application of the bonded composite patches effectively reduces the stress intensity factor (SIF) near the crack tip and hence retards or eliminates the crack propagation. As the chances of fracture are almost reduced, the life of the structures increases by almost double of the initial. The main advantage of this patch repair technology is that, it doesn’t increase the weight of the structure too much.
The present investigation deals with the static analysis of adhesively bonded inner tapered double lap joint in laminated FRP composites subjected to transverse loading using three-dimensional theory of elasticity based finite element method. Many researchers studied the influences of various parameters on the failure behaviour on the composites. In those studies, the typical bonding parameters are surface conditions, fillet, bond line thickness, and environmental conditions. In the present study the stresses and deformation characteristics of adhesively bonded inner tapered double lap joint made of generally and especially orthotropic laminates (FRP) subjected to transverse loading for the three different adhesive angles, three different adhesive thicknesses with different fibre angle orientations, i.e. the adhesive angles from 350 to 450 increased in steps of 50. The variation in stresses and deflection are studied when the fibre angle orientation is varied from 00 to 900 in steps of 150. The adhesive thickness varies from 0.05 to 0.15 insteps of 0.05mm. In all the above cases stresses and displacements at various locations are evaluated for the static boundary conditions
Study of Damage to ABS Specimens Submitted To Uniaxial Loadingtheijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
Theoretical work submitted to the Journal should be original in its motivation or modeling structure. Empirical analysis should be based on a theoretical framework and should be capable of replication. It is expected that all materials required for replication (including computer programs and data sets) should be available upon request to the authors.
The International Journal of Engineering & Science would take much care in making your article published without much delay with your kind cooperation.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
International Journal of Engineering Research and Development is an international premier peer reviewed open access engineering and technology journal promoting the discovery, innovation, advancement and dissemination of basic and transitional knowledge in engineering, technology and related disciplines.
Investigation on Divergent Exit Curvature Effect on Nozzle Pressure Ratio of ...IJERA Editor
The objective of this project work is to computationally analyze shock waves in the Convergent Divergent (CD) Nozzle. The commercial CFD code Fluent is employed to analyze the compressible flow through the nozzle. The analysis is about NPR (Nozzle Pressure Ratio) i.e., the ratio between exit pressure of the nozzle to ambient pressure. The various models of CD Nozzle are designed and the results are compared. The flow characteristic of shockwave for various design of CD Nozzle is also discussed. The purpose of this project is to investigate supersonic C-D nozzle flow for increasing NPR (Nozzle pressure ratio) through CFD. The imperfect matching between the pressures and ambient pressure and exit pressure leads to the formation of a complicated shock wave structure. Supersonic nozzle flow separation occurs in CD nozzles at NPR values far above their design value that results in shock formation inside the nozzle. The one-dimensional analysis approximations are not accurate, in reality the flow detaches from the wall and forms a separation region, subsequently the flow downstream becomes non-uniform and unstable. Shock wave affects flow performance of nozzle from NPR value 1.63 for existing geometrical conditions of nozzle. Problem of using this nozzle above 1.63NPR is shock wave at downstream of throat. After shock wave, static pressure increases further downstream of flow. It leads to flow separation and back pressure effects. Back pressure makes nozzle chocked. To investigate this problem, geometry of divergent portion is introduced and analysed through CFD. This is expected in resulting of reduction of flow separation and back pressure effect as well as increase in nozzle working NPR.
An Experimental Investigation into the Grindability Aspects of Newly Develope...IDES Editor
Ceramics are getting widely used in many engineering applications. These ceramic materials need to be ground. Unfortunately, the ground ceramic components mostly contain surface/subsurface damages. To minimize the grinding induced damages selection of appropriate grinding process parameters is very important. Ceramic composite material (AlSiTi) has been selected in the present study to investigate its grindability. This research work deals with the analysis of the process parameters such as wheel speed, table feed and infeed as influential factors, on the force components, grinding specific energy and surface roughness values based
on Taguchi’s experimental design method. Scanning electron microscopy (SEM) has been used to analyze the subsurface damages. The result provides valuable insight into the grindability aspects of the composite ceramic (AlSiTi).
Static Analysis of Single Lap Joint of Composite Materialsijsrd.com
Mechanically fastened joints are critical parts in composite aircraft structures. The composite structural members are highly used in the following applications such as aerospace, automobiles, marine, architecture etc., In the past decades, adhesive bonding is a practical joint method for joining composite materials which provide low shear and tensile strength .To improve the tensile strength, the joint is made with material joint. Glass Fiber/Chopped strands mat and Bi-Directional fly / Epoxy composite is fabricated by hand lay-up method. The tensile properties of the material joint are obtained and compared with that of bolted joint. The experimental results shows that the material joint has superior tensile properties than the bolted joint and the Bi-Directional fly composite exhibits superior tensile strength than the chopped strands mat. Finite element analysis also done and compared with the experimental results and found to be similar.
Size effect of plain concrete beams–an experimental studyeSAT Journals
Abstract
The paper analyses the size dependency of the fracture energy (GF) and the effective length of fracture process zone (Cf) of concrete
determined as per the Bazant’s Size effect method and RILEM Work-of-fracture methods. The fracture parameters (GF,Cf) are
determined by measuring the maximum loads of geometrically similar notched plain concrete (M25) specimens of different sizes in a
size ratio of 1:5 with different pre-cast notch depths (a/d=0.15, 0.30 and 0.45) under three point bending through load-deflection
curves. In each notch depth ratio, 15 beams are cast and tested with 03 similar specimens in each size of the beams. Total beams
tested are 45.The variation of both the fracture energy and the effective length of fracture process zone as a function of the specimen
size and notch depth is determined using Bazant’s Size effect method and RILEM Work-of-fracture method. Fracture energy and
Fracture process zone length determined by Size effect method are found to be decreasing with the increasing notch depth ratios.
Fracture energy calculated using Work-of-fracture method is increasing with the increase in size of specimen and decreasing with the
increasing notch depth ratios.
Vibrational Analysis Of Cracked Rod Having Circumferential Crack IDES Editor
The frequency ratio of torsional vibration of a rod without crack and of rod with crack subjected to torque at the free end for various crack depth and varying crack location is investigated. It is found that even a cracked of small depth is
dangerous at the fixed end, also as the crack depth is increases more than 50% of diameter of rod there is a considerable drop in natural frequency of the rod .
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 paper addresses the fracture toughness ( ), or also known as critical stress intensity Factor, according to
conditions of Lineal Elastic Fracture Mechanics (LEFM). The characterization of the mechanical properties in
tensile and fracture toughness of structural steel pipes API-5L used in hydrocarbons transportation was
performed. For fracture toughness, the material was tested through fatigue crack propagation on standardized
compact specimen (CT) according to ASTM E-399 norm. A thickness (B) equal to and a crack size (a) equal
to 0.5w were used. With the porpoise of establishing the adequate conditions at the crack tip, the specimens were
subjected to fatigue pre-cracking by application of repeated cycles of load in tensile-tensile and constant load
amplitude with a load ratio of R = 0.1. The experimental Compliance method was used based on data obtained
from load vs. Crack Mouth Opening Displacement (CMOD). The results show a Stress Intensity factor of 35.88
MPa√m for a 25 mm crack size specimen. The device used for testing is a MTS-810 machine with capacity of
100KN and 6 kHz sampling rate, which meets the conditions of the ASTM E-399 standard. The cracking
susceptibility of steel is influenced by the size, morphology and distribution of non-metallic inclusions,
thermochemical interaction with the environment and microstructure.
Finite Element Analysis of the Composite Patch Repairs of the PlatesIJERA Editor
Adhesively-bonded patches are used for repair of different types of damages such as holes, notches, scratches, cracks etc. occurring in metallic as well as composite structures. The composite patching is the most widely used method of restoring the load-carrying capacity of the weakened structure. Due to the rapid growth of aerospace industry, analysis of adhesively-bonded patches to repair cracked structures have been the focus for many years. Most of these studies investigated repaired structures using linear analysis and demonstrated the viability of adhesively-bonded patch-repairs as a means to improve the durability and damage tolerance of cracked metallic structures efficiently and economically.Many researchers performed more intensive research on the method and presented the advantages of a composite material patch used for the cracked plate repairing. It was found that the bonded patch method not only reduces the weight but also increases the service life.In this research work, the analysis of cracked metallic and composite plates which are repaired by bonded-composite patches is performed using Finite Element Analysis package FRANC2D/L. This package is available with its corresponding mesh generating program CACSA. They are developed by Cornel Fracture Group, Cornel University.In this study, various fracture parameters for the structures are found out. It revealed that, the application of the bonded composite patches effectively reduces the stress intensity factor (SIF) near the crack tip and hence retards or eliminates the crack propagation. As the chances of fracture are almost reduced, the life of the structures increases by almost double of the initial. The main advantage of this patch repair technology is that, it doesn’t increase the weight of the structure too much.
The present investigation deals with the static analysis of adhesively bonded inner tapered double lap joint in laminated FRP composites subjected to transverse loading using three-dimensional theory of elasticity based finite element method. Many researchers studied the influences of various parameters on the failure behaviour on the composites. In those studies, the typical bonding parameters are surface conditions, fillet, bond line thickness, and environmental conditions. In the present study the stresses and deformation characteristics of adhesively bonded inner tapered double lap joint made of generally and especially orthotropic laminates (FRP) subjected to transverse loading for the three different adhesive angles, three different adhesive thicknesses with different fibre angle orientations, i.e. the adhesive angles from 350 to 450 increased in steps of 50. The variation in stresses and deflection are studied when the fibre angle orientation is varied from 00 to 900 in steps of 150. The adhesive thickness varies from 0.05 to 0.15 insteps of 0.05mm. In all the above cases stresses and displacements at various locations are evaluated for the static boundary conditions
Study of Damage to ABS Specimens Submitted To Uniaxial Loadingtheijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
Theoretical work submitted to the Journal should be original in its motivation or modeling structure. Empirical analysis should be based on a theoretical framework and should be capable of replication. It is expected that all materials required for replication (including computer programs and data sets) should be available upon request to the authors.
The International Journal of Engineering & Science would take much care in making your article published without much delay with your kind cooperation.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
International Journal of Engineering Research and Development is an international premier peer reviewed open access engineering and technology journal promoting the discovery, innovation, advancement and dissemination of basic and transitional knowledge in engineering, technology and related disciplines.
Investigation on Divergent Exit Curvature Effect on Nozzle Pressure Ratio of ...IJERA Editor
The objective of this project work is to computationally analyze shock waves in the Convergent Divergent (CD) Nozzle. The commercial CFD code Fluent is employed to analyze the compressible flow through the nozzle. The analysis is about NPR (Nozzle Pressure Ratio) i.e., the ratio between exit pressure of the nozzle to ambient pressure. The various models of CD Nozzle are designed and the results are compared. The flow characteristic of shockwave for various design of CD Nozzle is also discussed. The purpose of this project is to investigate supersonic C-D nozzle flow for increasing NPR (Nozzle pressure ratio) through CFD. The imperfect matching between the pressures and ambient pressure and exit pressure leads to the formation of a complicated shock wave structure. Supersonic nozzle flow separation occurs in CD nozzles at NPR values far above their design value that results in shock formation inside the nozzle. The one-dimensional analysis approximations are not accurate, in reality the flow detaches from the wall and forms a separation region, subsequently the flow downstream becomes non-uniform and unstable. Shock wave affects flow performance of nozzle from NPR value 1.63 for existing geometrical conditions of nozzle. Problem of using this nozzle above 1.63NPR is shock wave at downstream of throat. After shock wave, static pressure increases further downstream of flow. It leads to flow separation and back pressure effects. Back pressure makes nozzle chocked. To investigate this problem, geometry of divergent portion is introduced and analysed through CFD. This is expected in resulting of reduction of flow separation and back pressure effect as well as increase in nozzle working NPR.
Since crowdfunding's emergence in the late 1990s, 4 types of verticals have appeared. With different terms and goals, it is necessary to understand the distinctions involved with each type of crowdfunding to make informed decisions.Learn more about this recent and fast-growing industry.
Design and Implementation of programmable Cardiac Pacemaker Using VHDLIJERA Editor
Pacemaker design has evolved very rapidly over the last several years. There has been a great deal of work in enhancing the programmability of pacemakers, to enable them to be programmed to work with different selected operating parameters, and indeed to work in different modes. In Taiwan, about 70%of cardiac pacemakerpatients are paced only from the ventricle with some pacing parameter programmability. This paper goal is to design a cardiac pacemaker with various NBG modes. A state machine approach has been followed to achieve the desired purpose. The pacemaker system is divide into three main sections i.e. controlling unit, sensing unit and pulse generator. In this paper we mainly concentrate on controlling unit and pulse generator. It has been developed using VHDL coding and implemented in hardware using FPGA. In a simple pacemaker process i.e. single chamber or dual chamber pacemaker, first an input signal or an event is detected in heart through leads. When the input signal is detected a timer generates a delay for approximately 0.8 sec. It is the time between two consecutive heartbeats, thus giving us 72 heartbeats per minute. Once the generated delay expires, sensing unit again start detecting a new event. If any event is detected we repeat the process of detection and waiting. If no event is detected we need to provide an electrical pulse to the heart and then repeat the whole process of detection and waiting. The code has been optimized and modified for different pacemaker modes.
Fluid Structural Modal Coupled Numerical Investigation of Transonic Flutterin...IJERA Editor
Flutter is an unstable oscillation which can lead to destruction. Flutter can occur on fixed surfaces, such as blades, wing or the stabilizer. By self-excited aeroelastic instability, flutter can lead to mechanical or structural failure of aircraft engine blades. The modern engines have been designed with increased pressure ratio and reduced weight in order to improve aerodynamic efficiency, resulting in severe aeroelastic problems. Particularly flutter in axial compressors with transonic flow can be characterized by a number of aerodynamic nonlinear effects such as shock boundary layer interaction, rotating stall, and tip vortex instability. Rotating blades operating under high centrifugal forces may also encounter structural nonlinearities due to friction damping and large deformations. In the future work a standard axial flow compressor blade will be taken for analysis, both Subsonic and Transonic range are taken for analysis. Fluid and Structure are two different domains which will be coupled by full system coupling technique to predict the fluttering effect on the compressor blade. ANSYS is a commercial simulation tool, which will be deployed in this work to perform FSI (Fluid Structure Interaction) and FSI coupled Modal to predict the flutter in the compressor blades
Influence of Thrust, Torque Responsible for Delamination in drilling of Glass...IDES Editor
Glass fabric sandwich composites are potentially
growing materials which satisfies the low strength to weight
fraction, thermal conductivity, high strength and long
operational lifetime required for key engineering applications
especially in the field of Mechanical and Aerospace structures.
With their wide range of application, their manufacturing
and machinability characteristics are interesting to
investigate. Drilling is one of the prime manufacturing
processes used in assembly lines of components for fastening
and joining two components. In this study, Glass Fabric – Epoxy
/ Rigid polyurethane foam sandwich hybrid composite is drilled
in Arix VMC 100 CNC drilling machine using High Speed
Steel (HSS) drill bit of three different diameters of 6 mm, 8
mm and 10 mm. A L9 orthogonal array is setup to investigate
the result. Two main parameters that contribute to
delamination are thrust and torque. Thus in this
investigation, thrust and torque responsible for the effect of
delamination and hole quality is studied experimentally.
Scanning Electron Microscope (SEM) images are taken for
the drilled hole laminate to support the result.
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
Experimental Determination of Fracture Energy by RILEM Methodtheijes
This paper deals with investigation of fracture energy (GF) of concrete. The study involves experimental determination of fracture energy (GF) by testing three point bend concrete beams of same size but varying notch to depth ratios. RILEM fracture energy (GF) and Stress Intensity factor values is determined
An Overview of Clearance Optimization in Sheet Metal Blanking ProcessIJMER
Abstract: This document prescribes a model investigation the effect of potential parameters influencing the blanking
process and their interaction. The blanking process optimization carried out by using Design of Experiment (DOE), Finite
Element Method (FEM) with ANSYS Package, Simulation with ABAQUS-Explicit software, Blank soft Software and Neural
Network Simulation in order to achieve the intended model objectives.
Keywords: Blanking Process, DOE, FEM, Optimum Clearance and Simulation.
Gaskets in joints play an important role in the sealing performance of bolted flange joints, and their behavior is
complex due to nonlinear material properties combined with permanent deformation. The variation of contact stresses due to
the pressure of the flange and the material properties of the gasket play important roles in achieving a leak proof joint. In this
paper, a three-dimensional finite element analysis (FEA) of bolted flange joints has been carried out by taking experimentally
obtained loading and unloading characteristics of the gaskets for various thicknesses and loads. Analysis shows that the
distribution of contact stress has a more dominant effect on sealing performance than the limit on flange rotation specified by
ASME.
Modelling and Analysis of Hybrid Composite Joint Using Fem in AnsysIOSR Journals
Abstract: Composite materials are widely used in the various Fields. Due to the high strength they are widely
used in the low weight constructions and also used as a suitable alternative to metals. In various applications
and also for joining various composite parts together, they are fastened together using adhesives or Mechanical
fasteners. Modeling and static analysis of 3-D Models of joints such as bonded, riveted and hybrid. The results
were found in terms of vonmises stress, shear stress, and normal stress for stress distribution. ANSYS FEA tool
has been used for stress distribution characteristics of various configurations of double riveted single lap joint
with three joining methods namely bonded, riveted and hybrid the present study deals with the analysis of single
lap joint subjected to the given tensile load and the stress distribution in the members under various design
conditions are found.
Finite Element Analysis of Damping Performance of VEM Materials Using CLD Tec...IJERA Editor
Most engineering structures experiences vibrational motion, this unwanted vibrations can result in premature
structural failure. Many methods are developed which enhances capability of damping such as constrained layer
damping. Shear motion is produced in VEM due to constraining layer to resist unwanted vibrational energy.
This paper shows theeffect of varying the thickness of viscoelastic materials on damping performance of CLD
beam.The damping performance is measured in terms of modal loss factor.
Influence of contact friction conditions on thin profile simulationVan Canh Nguyen
The paper presents the development of the Finite Element model for simulation of thin
aluminium profile extrusion of both solid and hollow shapes. The analysis has shown that the material
flow in simulation is very dependent on the friction model. Experimental and theoretical studies show
that friction traction on the interface between the tool and the deformed material can be represented as
a combination of adhesive friction force and the force that is required to deform surface asperities. In
aluminium extrusion we can clearly distinguish two different areas with respect to friction conditions
such as sticking and sliding and transient zones between them. The lengths of these zones are also
dependent on variation of the choke angle and actual thickness of the profile. To get these values the
material flow problem is to be coupled with the simulation of the tools deformation. A series of
experiments with specially designed tools have been done to investigate how the bearing length and
choke angle may influence the extension of different friction zones and by these means vary the
material flow pattern. The friction models have also been tested with industrial profiles of complex
shapes and have shown good correspondence to reality.
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Experimental and numerical evaluation of plasticity model with ductile damage to applied in project of shielding sheet metal.
1. Bruno Cesar Pockszevnicki Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 5, Issue 5, ( Part -6) May 2015, pp.173-176
www.ijera.com 173 | P a g e
Experimental and numerical evaluation of plasticity model with
ductile damage to applied in project of shielding sheet metal.
Bruno Cesar Pockszevnicki*, Pedro Américo Almeida Magalhães Júnior**
*(Mechanical Engineering Department, Pontifical Catholic University of MinasGerais,BeloHorizonte, Brazil)
**(Mechanical Engineering Department, Pontifical Catholic University of MinasGerais, Belo Horizonte, Brazil)
ABSTRACT
This work aims to develop a methodology for numerical evaluation via finite elements applied to projects shields
sheet metal. To validate the methodology physical test were conduct and were compare with the numerical
simulation. In the simulation, a plasticity material modelit was used at high strain rates, besides the insertion of a
damage model through forming limit diagram (FLD) to capture the initiation of damage and energy criteria for
propagation of the fracture. The tested shielding design is for the II-A protection level using the type 9mm
ammunition.
Keywords- Ballistic Impact, Finite Element, Plasticity, Damage, Blindage.
I. INTRODUCTION
In blindage projects for security and defense
area, different materials are employ to form the
solution of the shield. The understanding what
happens with each material inserted in solution is
necessary and desired. One part of the development
process more usedto evaluate project proposals are
experimental verifications.
Instead of only physical test, the generation of
numerical models using the finite element method
can be a great strategy to reduce time and cost,
optimizing resources and ensuring structural
performance, and enable increased understanding of
the ballistic impact phenomenon.
In the case of shields project the main
phenomenon to be study is structural impact with
perforation. To study perforation, a damage variable
to capture the penetration should be considered in the
model as the other numerous parameters and
mechanical properties that arerequired according [1]
when they usefinite element technique applied to
modeling shield composite.
Therefore, phenomenon and characterization of
materials are the variables to be study in
understanding the art of shielding. To start in the area
using the finite element method, one methodology is
present in this paper aimed at a portion of the
armored project in which only metal components are
used.
The first aim of studying, is start with metallic
materials where is possible to setup models capable
of describing the elastic-plastic behavior and damage,
providing evolution from the initiationof damage,
propagation until final damage, a perforation.
Thus, evaluation parameters are establish to have
a comparison between physical tests and numerical
simulation, the idea is to enable the use of modeling
for cases of shielding levelII-A [2], [3].
First is to present the experimental evaluation
performed using a projectile-type 9mm FMJ (Full
Metal Jacket) with ammo tip ogival.
Following is present equating of the plasticity
model with damage using the finite element
modeling. The results obtained are present in each
operation and a comparison between physical test and
numerical simulation is evaluate.
II. BALLISTIC IMPACT – PHYSICAL TEST
For the assessed physical test, it was consider a
dimension plate of300x300mm.It was tested two steel
plates, one called AISI / SAE 1010 with a thickness
of 2.9mm, and a steel dedicated to the shielding
called Ramor 500 with a thickness of 2.5mm.The test
was perform at a distance of 7m using a 9mm
projectile with ogival tip, mass 10.5g and the
theoretical speed of 384m/s.
From the impact, some measurements were
perform, the final thickness of the plate in impacted
area, also the final displacement caused by the
impact. In these tests, none perforation occur as
shown in Figures 1 and 2.
RESEARCH ARTICLE OPEN ACCESS
2. Bruno Cesar Pockszevnicki Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 5, Issue 5, ( Part -6) May 2015, pp.173-176
www.ijera.com 174 | P a g e
Fig. 1 – Steel plate of AISI/SAE 1010
Fig. 2 – Steel plate ofRamor 500
In figure 3 is show the densification obtained in
the thickness of steel AISI / SAE 1010, while the
plate Ramor500 steel did not show any change in
deformation. To evaluate the densification in
thickness, the plate was cut into the impact region to
ensure the final thickness measurement.
At steel Ramor500 only marks on the outer
surface were obtained from impact. No additional
testing was conducted, only the verification that this
steel with 2.5mm of thickness could be used
forblindage level II-A.
Only steel AISI/SAE 1010it was checked the
changing of cross section. The final thickness
measured on the plate was 2.6mm.
Fig. 3 – Cut of plate in region of impact
III. FINITE ELEMENT MODELING
The problem of finite element was develop in the
framework of the dynamics, using explicit integration
algorithm. Elements of shell typewith a high degree
of refinement in the impact area used, 0.1mm of
refinement in the impact region, as shown in Figure
4.
Fig. 4 – Type of mesh refinement adopted
The plasticity model used is the Johnson-Cook
that consider the effect of the strainrate𝜀, the
initiation of damage is governed by the formulation
of the FLD forming limit curve and the propagation
of damage based on the strain energy.The plasticity's
law from is given by equation 1.
𝜎 = 𝐴 + 𝐵 𝜀 𝑝
𝑛
1 + 𝑐𝑙𝑛
𝜀
𝜀𝑜
(1)
where,
𝐴, is yield stress;
𝐵, is hardening coefficient;
𝑛, exponent of hardening;
𝑐, coefficient of strain rate
𝜀0, strain rate of reference.
The initiation criterion of damage, is introduced
via forming limit curve that starts when the
variableFLD =1.The forming limit diagram was
proposedby Keeler andBackofen in 1964 [4], that is
used to measure the amount of material that resists to
deformation before the initiation of necking, as
shown in Figure 5.
Fig. 5 – FLD, FormingLimitDiagram
Where:
FLD, state variable of damage, which increases
with plastic deformation.
𝜔 𝐹𝐿𝐷 =
𝜀 𝑚 á𝑥𝑖𝑚𝑎
𝜀 𝐹𝐿𝐷
𝑚 á𝑥𝑖𝑚𝑎 (𝜀 𝑚 í𝑛𝑖𝑚𝑎 ,𝜃)
(2)
3. Bruno Cesar Pockszevnicki Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 5, Issue 5, ( Part -6) May 2015, pp.173-176
www.ijera.com 175 | P a g e
major, maximum deformation limit,
minor, minimum deformation limit;
Already, the formulating of damage
propagationusedis the one proposed by Hillerborg
(1976) [5] where it uses the fracture energyGf given
by:
𝐺𝑓 = 𝜎𝑦 𝑑𝑢𝑓
𝑢 𝑓
0
(3)
At this equation,uf is the plastic equivalent
displacement, and it is consider through following
rule:
Before damage start:𝑢𝑓 = 0
After damage start:𝑢𝑓 =
2𝐺 𝑓
𝜎 𝑦
At fracture:𝑢𝑓 =
2𝐺 𝑓
𝜎 𝑦
𝜎𝑦 , is yield stress,
The graph of Figure 6 shows the relationship
between stress and plastic displacement of fracture.
Fig. 6 - Fracture energy evolution
The law of evolution of the stresses with damage
is given by equation 4.
𝜎 𝑑
= (1 − 𝑑)𝜎 𝑢
(4)
where:
𝜎 𝑑
, is a stress damaged and 𝜎 𝑢
a stress
undamaged.
𝑑,is a damage variable.
IV. RESULTS
According to physical test evaluation, the
maximum displacement measured was 10.5mm in
curvature, presented at figure 7.The final thickness
measured at the center of impact region was 2.6mm.
It was proposed,a form of the measuring the
maximum displacementconsidering thickness.
Fig. 7 - Measurement of the displacement due to the
impact.
In numerical modeling via finite element
method, the maximum displacement was 10.32mm,
figure 8, and final thickness evaluated at impact
region was 2.49mm, figure 9.
To expose the gain of the analysis using the
elastic-plastic model with damage, rather than the
conventional plasticity in Figure 10, is present a
simulation considering a model material without any
law of damage evolution and without the inclusion of
deformation rate effect.
Fig. 8 –Total displacement on the plate, curvature
displacement.
Fig. 9 - Final thickness of plate in simulation
Fig. 10 - Result of curvature displacement for
conventional plasticity
V. CONCLUSION
The shell element used to modeling plasticity
and damage via finite element method presented
values with a higher degree of correlation than 95%,
while the use of the conventional plasticity the
response was quite different. The use of shell
elements to capture the behavior of the material
proposed due to the low computational cost, unlike
the approach using solid elements.
4. Bruno Cesar Pockszevnicki Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 5, Issue 5, ( Part -6) May 2015, pp.173-176
www.ijera.com 176 | P a g e
Noted that the deformation rate must be
employed, and to modeling a component in fracture
situation, the inclusion of damage variable is highly
recommended.
The accuracy of the results is drive by the use of
elastic-plastic curves for different strain rates as more
curves are used, better the model describe structural
behavior.
As for the criterion of damage initiation is
necessary a caveat, because a good characterization
of deformation limits, maximum and minimum
deformation to predict beginning of material necking,
as established by the forming limit diagram FLD also
assist in better representation damage.
The energy criterion for the damage propagation
is use due to an attempt to make the nondependent
problem of mesh size even adopting a high
refinement in the impact area.
This methodology becomes possible, after the
calibration of material model, the useof finite element
method for verification of different types of
projectiles. Also provides a prediction of the final
displacement field and with the model is able to study
the structural behavior of metal sheets during an
impact ballistic. Finally, assist the armored project to
avoid perforations.
Acknowledgements
Grateful for professorPedro by support and PUC
Minas, CAPES, and companies Vision Graphic
andRuukki. Also thankful to Brazilian Federal Police
and TiroUrbano Defensive School.
REFERENCES
[1] B. Gama, J. Gillespie, Finite element
modeling of impact, damage evolution and
penetration of thick-section composites,
International Journal of Impact
Engineering, 38(4), 2011, 181-197.
[2] Norma NEB/T E-316, Proteção Balística de
Carros de Passeio, CTEX, 200.
[3] NIJ Standard-0101.06, Ballistic Resistance
of Body Armor,U.S. Department of
Justice,1985.
[4] S. P. Keeler, A. Backofen, Plastic instability
and fracture in sheets stretched over rigid
punches, ASM Transactions Quarterly, 56,
25–48, 1964.
[5] A. Hillerborg, M. Modeer, P.E. Petersson,
Analysis of Crack Formation and Crack
Growth in Concrete by Means of Fracture
Mechanics and Finite Elements, Cement and
Concrete Research, 6, 773–782, 1976.