This presentation sums up the proposed method to estimate the dynamic impacts on railway tracks. This work progressing by the inclusion of wheel stiffness and damping as well as the contact duration between the wheel and the rail.
The document presents a dynamic model for lifting railway tracks as a one-mass system. It derives the equation of motion for the model numerically using a Runge-Kutta integration scheme. The model accounts for parameters like mass, stiffness, damping, and lifting force. Numerical solutions show that damping coefficients affect the duration and quality of lifting, while lifting forces impact the lift value and duration. The dynamic model allows studying how system parameters influence behavior and stability during railway track lifting.
This document presents a method for designing a variable coupler curve four-bar mechanism that can generate different desired coupler curves through continuous adjustment of link lengths. The method involves replacing one link with an adjustable screw-nut link driven by a servomotor. Different coupler curves can be generated by controlling the angular displacement of the driving link and adjusting the length of the adjustable link. Equations are derived to calculate the required driving link angles and adjustable link lengths corresponding to desired coupler curves. Examples applying this mechanism to deburring pipes with non-circular cross-sections are provided.
IRJET- Seismic Analysis of Curve Cable-Stayed BridgeIRJET Journal
1) The document analyzes the seismic performance of cable-stayed bridges with different horizontal curvatures, ranging from straight to 5 degrees of curvature.
2) Six bridge models were analyzed using the software SAP2000, including a straight bridge and bridges with 1, 2, 3, 4, and 5 degrees of curvature.
3) The results show that base shear, pier displacement, and deck displacement all decreased as curvature increased from straight to 3 degrees, but then increased again from 3 to 5 degrees of curvature. The bridges with intermediate (2-3 degree) curvature demonstrated the best seismic performance.
Measuring Axle Weight of Moving Vehicle Based on Particle Swarm OptimizationIJRES Journal
The dynamic tire forces are the important factor influencing weigh-in-motion of vehicle. This paper presents a method to separate the dynamic tire forces contained in axle-weight signal. On the basis of analyzing the characteristic of axle-weight signal, the model of axle-weight signal and the objective function are constructed. After introducing the principle of particle swarm optimization (PSO), an improved PSO is employed to estimate the unknown parameters of the objective function. According to the obtained estimates of parameters, the dynamic tire forces contained in axle-weight signal are reconstructed. Subtract the reconstructed dynamic tire forces from the axle-weight signal, and get the estimate of axle weight of moving vehicle. Simulation and field experiments are conducted to demonstrate the performance of the proposed method.
1. The document presents the results of a finite element analysis modeling the behavior of reinforced concrete beam-column joints.
2. The analysis examined beam depths of 10, 12, and 14 inches and calculated the moment-rotation relationship for each.
3. The results showed that as beam depth increased, the moment capacity of the beam-column joint also increased. Deeper beams resulted in joints that could withstand higher moments before rotation.
This document discusses different types of gear trains, including simple, compound, reverted, and epicyclic gear trains. It provides details on how to calculate the speed ratio and train value for simple and compound gear trains. For simple gear trains, the speed ratio is the ratio of the number of teeth on the gears, and intermediate gears do not affect the speed ratio. Compound gear trains can provide a larger speed reduction compared to simple gear trains using smaller gears. The document also covers designing spur gears for a given velocity ratio and center distance between shafts.
Study on Vibration Reduction Effect of the Rail Vehicle with Axle Dynamic Vib...IJRES Journal
To reduce the vertical vibration of the vehicle, the vehicle model including the axle dynamic
vibration absorber is established, and the vertical vibration acceleration spectrum of the wheel, the steering
frame and the body is obtained by numerical simulation. The vibration reduction effect of the dynamic vibration
absorber is analyzed. The results show that the axle dynamic vibration absorber not only has a good vibration
reduction effect on the wheel, but also has an important effect on the vertical vibration of the bogie and the
vehicle body.
Performance Evaluation of Elastomeric Pads as Bridge Bearings under Earthquak...IRJET Journal
1) The document evaluates the performance of bridges with elastomeric pads as bearings compared to bridges with reinforced concrete (RC) bearings under earthquake loads through numerical modeling and analysis.
2) The analysis found that bridges with elastomeric pads had lower time periods, pier moments, lateral pier forces, and total displacements compared to bridges with RC bearings. For example, time period was 59.2% lower and displacement was 32.4% lower for bridges with elastomeric pads.
3) In general, the percentage reductions in response were greater for taller piers. It was concluded that elastomeric pads perform better seismically than RC bearings for bridges.
The document presents a dynamic model for lifting railway tracks as a one-mass system. It derives the equation of motion for the model numerically using a Runge-Kutta integration scheme. The model accounts for parameters like mass, stiffness, damping, and lifting force. Numerical solutions show that damping coefficients affect the duration and quality of lifting, while lifting forces impact the lift value and duration. The dynamic model allows studying how system parameters influence behavior and stability during railway track lifting.
This document presents a method for designing a variable coupler curve four-bar mechanism that can generate different desired coupler curves through continuous adjustment of link lengths. The method involves replacing one link with an adjustable screw-nut link driven by a servomotor. Different coupler curves can be generated by controlling the angular displacement of the driving link and adjusting the length of the adjustable link. Equations are derived to calculate the required driving link angles and adjustable link lengths corresponding to desired coupler curves. Examples applying this mechanism to deburring pipes with non-circular cross-sections are provided.
IRJET- Seismic Analysis of Curve Cable-Stayed BridgeIRJET Journal
1) The document analyzes the seismic performance of cable-stayed bridges with different horizontal curvatures, ranging from straight to 5 degrees of curvature.
2) Six bridge models were analyzed using the software SAP2000, including a straight bridge and bridges with 1, 2, 3, 4, and 5 degrees of curvature.
3) The results show that base shear, pier displacement, and deck displacement all decreased as curvature increased from straight to 3 degrees, but then increased again from 3 to 5 degrees of curvature. The bridges with intermediate (2-3 degree) curvature demonstrated the best seismic performance.
Measuring Axle Weight of Moving Vehicle Based on Particle Swarm OptimizationIJRES Journal
The dynamic tire forces are the important factor influencing weigh-in-motion of vehicle. This paper presents a method to separate the dynamic tire forces contained in axle-weight signal. On the basis of analyzing the characteristic of axle-weight signal, the model of axle-weight signal and the objective function are constructed. After introducing the principle of particle swarm optimization (PSO), an improved PSO is employed to estimate the unknown parameters of the objective function. According to the obtained estimates of parameters, the dynamic tire forces contained in axle-weight signal are reconstructed. Subtract the reconstructed dynamic tire forces from the axle-weight signal, and get the estimate of axle weight of moving vehicle. Simulation and field experiments are conducted to demonstrate the performance of the proposed method.
1. The document presents the results of a finite element analysis modeling the behavior of reinforced concrete beam-column joints.
2. The analysis examined beam depths of 10, 12, and 14 inches and calculated the moment-rotation relationship for each.
3. The results showed that as beam depth increased, the moment capacity of the beam-column joint also increased. Deeper beams resulted in joints that could withstand higher moments before rotation.
This document discusses different types of gear trains, including simple, compound, reverted, and epicyclic gear trains. It provides details on how to calculate the speed ratio and train value for simple and compound gear trains. For simple gear trains, the speed ratio is the ratio of the number of teeth on the gears, and intermediate gears do not affect the speed ratio. Compound gear trains can provide a larger speed reduction compared to simple gear trains using smaller gears. The document also covers designing spur gears for a given velocity ratio and center distance between shafts.
Study on Vibration Reduction Effect of the Rail Vehicle with Axle Dynamic Vib...IJRES Journal
To reduce the vertical vibration of the vehicle, the vehicle model including the axle dynamic
vibration absorber is established, and the vertical vibration acceleration spectrum of the wheel, the steering
frame and the body is obtained by numerical simulation. The vibration reduction effect of the dynamic vibration
absorber is analyzed. The results show that the axle dynamic vibration absorber not only has a good vibration
reduction effect on the wheel, but also has an important effect on the vertical vibration of the bogie and the
vehicle body.
Performance Evaluation of Elastomeric Pads as Bridge Bearings under Earthquak...IRJET Journal
1) The document evaluates the performance of bridges with elastomeric pads as bearings compared to bridges with reinforced concrete (RC) bearings under earthquake loads through numerical modeling and analysis.
2) The analysis found that bridges with elastomeric pads had lower time periods, pier moments, lateral pier forces, and total displacements compared to bridges with RC bearings. For example, time period was 59.2% lower and displacement was 32.4% lower for bridges with elastomeric pads.
3) In general, the percentage reductions in response were greater for taller piers. It was concluded that elastomeric pads perform better seismically than RC bearings for bridges.
This document summarizes a study that analyzed the flow behavior and aerodynamic performance of a three-bucket helical Savonius rotor at different twist angles using computational fluid dynamics (CFD). A 3D model of a rotor with 90-degree twist was constructed and simulated at various rotor angles. High pressure and velocity were observed on the advancing bucket at a rotor angle of 30 degrees, resulting in maximum positive torque. The study aims to increase efficiency at all rotor angles through the use of a helical design compared to a conventional Savonius rotor.
This document outlines the content for a course on pavement design called CEE320 at Washington State University. It covers topics such as the purpose and significance of pavements, types of pavement materials and structures, design methods, and an example design problem. The course will discuss flexible and rigid pavements, parameters for pavement design, and use the AASHTO empirical and mechanistic-empirical methods. References listed include a highway engineering textbook and guides from the Washington State Department of Transportation and Asphalt Pavement Association.
The Effect of Arm Stiffness on the Elasto-Kinematic Properties of Single-Axle...theijes
The paper is focused on the stiffness analysis of the longitudinal arm of single-axle suspension on elastokinematic behaviour of the vehicle axle which is highly important when considering the handling characteristics related tovehicle safety.The elasto-kinematic behaviour of the axle determines the course of the geometrical parameters of wheel suspension, the toe angle and camber as the function of wheel movement during force loading. This paper presents the complex MBS (Multi-Body Simulation)model of the wheel suspension with nonlinear characteristics of rubber-metal bushings. The model also comprises force elements such as springs, shock absorbers, stops and the transverse stabilizer. The model of flexible arm is implemented in the MBS model using the Craig-Bampton method, which represents a flexible body based on the synthesis of its own modal shapes. Subsequently,elasto-kinematic simulations are performed with the help ofthe computational system Hyperwork. The computational part of the paper presents the results of the elasto-kinematic behaviour of wheel axle for the flexible arm with different sheet metal thicknesses (2, 3 and 4 mm) and different materials (steel and aluminium alloy AlSi7Mg). Individual calculation models are compared to each other and also to the model of suspension with therigidarm. Elasto-kinematic analyses are also validated by the measurement inthe testing stage.
This document summarizes the kinematics analysis of a 3-UPU (universal-prismatic-universal) parallel robot. Each of the robot's three legs consists of two universal joints connected by a prismatic joint. The document establishes recursive matrix relations for solving the inverse kinematics problem given the position of the mobile platform. Simulation graphs are generated for the input displacements, velocities, and accelerations. The kinematics analysis determines the nine independent variables that define the robot's configuration based on vector-loop equations relating the joint parameters and platform position.
International Journal of Engineering and Science Invention (IJESI)inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
"Finding the influence line for a bridge based on random traffic and field me...TRUSS ITN
The influence line of a structure reflects its structural behaviour as well as any possible damage present on the bridge. An iterative algorithm is presented in this paper in order to obtain the shape of the influence line of a bridge together with the load distribution of trucks passing overhead. One great advantage of this approach is that sensor calibration with pre-weighed trucks can be avoided. The only initial information needed are the measurement data and a preliminary estimate of influence line based on engineering judgement. An illustrative example is shown, where strain data have been collected on a reinforced concrete culvert. Apart from the efficiency of the proposed algorithm, the influence of the temperature on the results is also shown.
Optimal Control for Torpedo Motion based on Fuzzy-PSO Advantage TechnicalTELKOMNIKA JOURNAL
The torpedo is a nonlinear object which is very difficult to control. Via to manage the rudder angle yaw, the diving plane angle, and the fin shake reduction, the torpedo yaw horizontal, the depth vertical and roll damping of the system are controlled accurately and steadily. In this paper, the particle swarm optimization is used to correct the imprecision of architecture fuzzy parameters. The coverage width of membership function and the overlap degree influence of neighboring membership functions are considered in the method to adjust dynamically from the system errors. Thereby optimizing the control signal and enhancing the torpedo motion quality. The proposed method results in a better performance compared to the other control method such as adaptive fuzzy-neural that proved effective of the proposed controller.
This document summarizes a master's thesis on dynamic modeling of freight wagons. It was written by Saeed Hossein Nia at Blekinge Institute of Technology in Sweden under the supervision of Ansel Berghuvud, Sebastian Stichel, and Thomas Nordmark. The thesis aims to enhance understanding of vehicle-track interaction for Swedish iron ore freight wagons operating on concrete and wooden sleepers in different weather conditions. It develops a multibody simulation model of the freight wagon and track, validates the model using measurements, and investigates potential sources of rolling contact fatigue on wheels, particularly during winters.
The group analyzed a 3D concrete overpass using MSC Patran/Nastran software. They applied a distributed load of 4,000 lb/in to simulate traffic, finding a maximum stress of 3,540 psi for the test geometry. Additional geometries were also analyzed. Applying a load of 80,000 lb/in to simulate a tractor-trailer resulted in complete failure at 71,000 psi. The analysis suggests using a semicircular archway, as it had the lowest stress of around 2,750 psi due to a larger cross-sectional area.
This document proposes a modified crawl gait technique for quadruped robots to achieve omnidirectional walking with increased stability compared to conventional methods. The conventional crawl gait has a stability margin of zero for some steps, making it unstable. The modified technique plans leg sequences and motions to maintain a positive stability margin at all times. It formulates the relationships between stability margin, stride length, and duty factor. Computer simulations and experiments on an actual quadruped robot validate that the modified crawl gait realizes omnidirectional walking with improved stability over uneven terrain.
International Journal of Computational Engineering Research(IJCER)ijceronline
International Journal of Computational Engineering Research (IJCER) is dedicated to protecting personal information and will make every reasonable effort to handle collected information appropriately. All information collected, as well as related requests, will be handled as carefully and efficiently as possible in accordance with IJCER standards for integrity and objectivity.
SLAM of Multi-Robot System Considering Its Network Topologytoukaigi
This document proposes a new solution to the multi-robot simultaneous localization and mapping (SLAM) problem that takes into account the network topology between robots. Previous multi-robot SLAM research has expanded one-robot SLAM algorithms without considering how the relationship between robots changes over time. The proposed approach models the network structure and derives the mathematical formulation for estimating the multi-robot SLAM. It presents motion and observation update equations in an information filter framework that can be implemented in a decentralized way on individual robots. Future work will focus on specific challenges in multi-robot SLAM like map merging.
IRJET- Four Propellers Submarine Drone ModellingIRJET Journal
This document summarizes a study on modeling and simulating a four-propeller submarine drone using Matlab. It presents the mathematical modeling of the submarine's kinematics and dynamics. The kinematic model describes the vehicle's motion and orientation using Euler angles. The dynamic model accounts for forces like weight, buoyancy and thrust from the four propellers. The simulation aims to analyze the submarine's behavior under different propeller configurations to validate the multi-thruster propulsion system architecture.
The document contains 50 questions and answers related to railway engineering. It covers topics like different types of railway tracks, signaling systems, track components, track geometry parameters, track maintenance practices and locomotive components. The questions are multiple choice type with one correct option out of the four options given under each question.
This document discusses optimizing haul road design for resource development projects in Northern Canada. It focuses on the interactions between ultra-heavy dump trucks and haul roads as a single transportation system. Stiffer road pavements can reduce rolling resistance and fuel consumption for trucks by decreasing deflection. The Critical Strain Method is advocated for more sophisticated pavement design over traditional CBR methods to model strains from heavy truck loads. A full-scale experiment is proposed to verify predicted displacements, stresses, and strains from this design method for ultra-heavy loading.
Vibration Analysis and Human Comfort Evaluation of Steel-Concrete Composite F...IJERA Editor
This work aims the development of an analysis methodology to investigate the dynamic behaviour of steelconcrete composite footbridges. The composite footbridge dynamic response is analysed based on two different strategies. Firstly, the traditional simulation of human walking, without consideration of the pedestrianfootbridge dynamic interaction effect is considered. On the other hand, the effect of the dynamics of the pedestrians while crossing footbridges in crowd situations is analysed and the pedestrian-footbridge dynamic interaction, based on the use of biodynamic models is investigated using a second strategy. The investigated structural system corresponds to an existing pedestrian footbridge built on Ayrton Senna Av. in the city of Rio de Janeiro/RJ, Brazil, with a central span of 68.6m. The footbridge dynamic response was obtained and compared to the limiting values proposed by several authors and design standards. The results indicate that the biodynamic loading models lead to peak accelerations values lower than those produced by the traditional methods. These results provided evidence that the pedestrian-structure dynamic interaction effect should be considered when composite footbridges are subjected to flow of pedestrians.
The static loading test bengt h. felleniuscfpbolivia
The document discusses instrumentation and interpretation of static loading pile tests. It provides details on different methods for determining pile capacity from load-movement curves. It also discusses using strain gauges and telltales to measure load distribution in piles. Group effects are illustrated with examples showing how load-movement curves change from single pile to group tests. Determining the modulus of concrete from strain measurements during testing is also covered.
Track junctions transfer rail vehicles between tracks or allow them to cross tracks. There are several types of simple track layouts for junctions depending on traffic needs. Common layouts include turnouts that continue or change the direction of travel, symmetrical splits that divert tracks in two directions with equal radii, and three-throw switches that allow movement in three directions but are now obsolete due to safety concerns. More advanced layouts include double turnouts, diamond crossings, scissors crossovers, triangles, and double junctions.
OPTIMIZATION OF PRESTRESSED CONCRETE BEAMS-student vincenzo robertiVincenzo Roberti
This document summarizes a student's final report on optimizing the design of prestressed concrete beams. The student formulated the problem using nonlinear programming to minimize the cost of the beam based on design variables like section dimensions and amount of prestressing steel. Constraints included practical bounds on dimensions and strength requirements. Standard and idealized beam sections were analyzed. Results found that a double tee section minimized cost and increasing concrete strength reduced cost for T-beams with 7 ksi concrete being optimal. Standard sections analysis confirmed idealized section results. The student concluded the idealized section optimization provided effective guidance to find the lowest cost standard beam section design.
Tc 202-transportation geotechnics and geoecology conferenceOzgur Bezgin
This presentation presents the concept of "Impact Reduction Factor" and the "Bezgin Impact Factor" to estimate vertical impact forces on railways due to track profile variation.
This presentation introduces the concept of "impact reduction factor" and a new method that are both developed by Dr. Niyazi Özgür Bezgin to estimate vertical impact forces on railways due to track stiffness variations.
This document summarizes a study that analyzed the flow behavior and aerodynamic performance of a three-bucket helical Savonius rotor at different twist angles using computational fluid dynamics (CFD). A 3D model of a rotor with 90-degree twist was constructed and simulated at various rotor angles. High pressure and velocity were observed on the advancing bucket at a rotor angle of 30 degrees, resulting in maximum positive torque. The study aims to increase efficiency at all rotor angles through the use of a helical design compared to a conventional Savonius rotor.
This document outlines the content for a course on pavement design called CEE320 at Washington State University. It covers topics such as the purpose and significance of pavements, types of pavement materials and structures, design methods, and an example design problem. The course will discuss flexible and rigid pavements, parameters for pavement design, and use the AASHTO empirical and mechanistic-empirical methods. References listed include a highway engineering textbook and guides from the Washington State Department of Transportation and Asphalt Pavement Association.
The Effect of Arm Stiffness on the Elasto-Kinematic Properties of Single-Axle...theijes
The paper is focused on the stiffness analysis of the longitudinal arm of single-axle suspension on elastokinematic behaviour of the vehicle axle which is highly important when considering the handling characteristics related tovehicle safety.The elasto-kinematic behaviour of the axle determines the course of the geometrical parameters of wheel suspension, the toe angle and camber as the function of wheel movement during force loading. This paper presents the complex MBS (Multi-Body Simulation)model of the wheel suspension with nonlinear characteristics of rubber-metal bushings. The model also comprises force elements such as springs, shock absorbers, stops and the transverse stabilizer. The model of flexible arm is implemented in the MBS model using the Craig-Bampton method, which represents a flexible body based on the synthesis of its own modal shapes. Subsequently,elasto-kinematic simulations are performed with the help ofthe computational system Hyperwork. The computational part of the paper presents the results of the elasto-kinematic behaviour of wheel axle for the flexible arm with different sheet metal thicknesses (2, 3 and 4 mm) and different materials (steel and aluminium alloy AlSi7Mg). Individual calculation models are compared to each other and also to the model of suspension with therigidarm. Elasto-kinematic analyses are also validated by the measurement inthe testing stage.
This document summarizes the kinematics analysis of a 3-UPU (universal-prismatic-universal) parallel robot. Each of the robot's three legs consists of two universal joints connected by a prismatic joint. The document establishes recursive matrix relations for solving the inverse kinematics problem given the position of the mobile platform. Simulation graphs are generated for the input displacements, velocities, and accelerations. The kinematics analysis determines the nine independent variables that define the robot's configuration based on vector-loop equations relating the joint parameters and platform position.
International Journal of Engineering and Science Invention (IJESI)inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
"Finding the influence line for a bridge based on random traffic and field me...TRUSS ITN
The influence line of a structure reflects its structural behaviour as well as any possible damage present on the bridge. An iterative algorithm is presented in this paper in order to obtain the shape of the influence line of a bridge together with the load distribution of trucks passing overhead. One great advantage of this approach is that sensor calibration with pre-weighed trucks can be avoided. The only initial information needed are the measurement data and a preliminary estimate of influence line based on engineering judgement. An illustrative example is shown, where strain data have been collected on a reinforced concrete culvert. Apart from the efficiency of the proposed algorithm, the influence of the temperature on the results is also shown.
Optimal Control for Torpedo Motion based on Fuzzy-PSO Advantage TechnicalTELKOMNIKA JOURNAL
The torpedo is a nonlinear object which is very difficult to control. Via to manage the rudder angle yaw, the diving plane angle, and the fin shake reduction, the torpedo yaw horizontal, the depth vertical and roll damping of the system are controlled accurately and steadily. In this paper, the particle swarm optimization is used to correct the imprecision of architecture fuzzy parameters. The coverage width of membership function and the overlap degree influence of neighboring membership functions are considered in the method to adjust dynamically from the system errors. Thereby optimizing the control signal and enhancing the torpedo motion quality. The proposed method results in a better performance compared to the other control method such as adaptive fuzzy-neural that proved effective of the proposed controller.
This document summarizes a master's thesis on dynamic modeling of freight wagons. It was written by Saeed Hossein Nia at Blekinge Institute of Technology in Sweden under the supervision of Ansel Berghuvud, Sebastian Stichel, and Thomas Nordmark. The thesis aims to enhance understanding of vehicle-track interaction for Swedish iron ore freight wagons operating on concrete and wooden sleepers in different weather conditions. It develops a multibody simulation model of the freight wagon and track, validates the model using measurements, and investigates potential sources of rolling contact fatigue on wheels, particularly during winters.
The group analyzed a 3D concrete overpass using MSC Patran/Nastran software. They applied a distributed load of 4,000 lb/in to simulate traffic, finding a maximum stress of 3,540 psi for the test geometry. Additional geometries were also analyzed. Applying a load of 80,000 lb/in to simulate a tractor-trailer resulted in complete failure at 71,000 psi. The analysis suggests using a semicircular archway, as it had the lowest stress of around 2,750 psi due to a larger cross-sectional area.
This document proposes a modified crawl gait technique for quadruped robots to achieve omnidirectional walking with increased stability compared to conventional methods. The conventional crawl gait has a stability margin of zero for some steps, making it unstable. The modified technique plans leg sequences and motions to maintain a positive stability margin at all times. It formulates the relationships between stability margin, stride length, and duty factor. Computer simulations and experiments on an actual quadruped robot validate that the modified crawl gait realizes omnidirectional walking with improved stability over uneven terrain.
International Journal of Computational Engineering Research(IJCER)ijceronline
International Journal of Computational Engineering Research (IJCER) is dedicated to protecting personal information and will make every reasonable effort to handle collected information appropriately. All information collected, as well as related requests, will be handled as carefully and efficiently as possible in accordance with IJCER standards for integrity and objectivity.
SLAM of Multi-Robot System Considering Its Network Topologytoukaigi
This document proposes a new solution to the multi-robot simultaneous localization and mapping (SLAM) problem that takes into account the network topology between robots. Previous multi-robot SLAM research has expanded one-robot SLAM algorithms without considering how the relationship between robots changes over time. The proposed approach models the network structure and derives the mathematical formulation for estimating the multi-robot SLAM. It presents motion and observation update equations in an information filter framework that can be implemented in a decentralized way on individual robots. Future work will focus on specific challenges in multi-robot SLAM like map merging.
IRJET- Four Propellers Submarine Drone ModellingIRJET Journal
This document summarizes a study on modeling and simulating a four-propeller submarine drone using Matlab. It presents the mathematical modeling of the submarine's kinematics and dynamics. The kinematic model describes the vehicle's motion and orientation using Euler angles. The dynamic model accounts for forces like weight, buoyancy and thrust from the four propellers. The simulation aims to analyze the submarine's behavior under different propeller configurations to validate the multi-thruster propulsion system architecture.
The document contains 50 questions and answers related to railway engineering. It covers topics like different types of railway tracks, signaling systems, track components, track geometry parameters, track maintenance practices and locomotive components. The questions are multiple choice type with one correct option out of the four options given under each question.
This document discusses optimizing haul road design for resource development projects in Northern Canada. It focuses on the interactions between ultra-heavy dump trucks and haul roads as a single transportation system. Stiffer road pavements can reduce rolling resistance and fuel consumption for trucks by decreasing deflection. The Critical Strain Method is advocated for more sophisticated pavement design over traditional CBR methods to model strains from heavy truck loads. A full-scale experiment is proposed to verify predicted displacements, stresses, and strains from this design method for ultra-heavy loading.
Vibration Analysis and Human Comfort Evaluation of Steel-Concrete Composite F...IJERA Editor
This work aims the development of an analysis methodology to investigate the dynamic behaviour of steelconcrete composite footbridges. The composite footbridge dynamic response is analysed based on two different strategies. Firstly, the traditional simulation of human walking, without consideration of the pedestrianfootbridge dynamic interaction effect is considered. On the other hand, the effect of the dynamics of the pedestrians while crossing footbridges in crowd situations is analysed and the pedestrian-footbridge dynamic interaction, based on the use of biodynamic models is investigated using a second strategy. The investigated structural system corresponds to an existing pedestrian footbridge built on Ayrton Senna Av. in the city of Rio de Janeiro/RJ, Brazil, with a central span of 68.6m. The footbridge dynamic response was obtained and compared to the limiting values proposed by several authors and design standards. The results indicate that the biodynamic loading models lead to peak accelerations values lower than those produced by the traditional methods. These results provided evidence that the pedestrian-structure dynamic interaction effect should be considered when composite footbridges are subjected to flow of pedestrians.
The static loading test bengt h. felleniuscfpbolivia
The document discusses instrumentation and interpretation of static loading pile tests. It provides details on different methods for determining pile capacity from load-movement curves. It also discusses using strain gauges and telltales to measure load distribution in piles. Group effects are illustrated with examples showing how load-movement curves change from single pile to group tests. Determining the modulus of concrete from strain measurements during testing is also covered.
Track junctions transfer rail vehicles between tracks or allow them to cross tracks. There are several types of simple track layouts for junctions depending on traffic needs. Common layouts include turnouts that continue or change the direction of travel, symmetrical splits that divert tracks in two directions with equal radii, and three-throw switches that allow movement in three directions but are now obsolete due to safety concerns. More advanced layouts include double turnouts, diamond crossings, scissors crossovers, triangles, and double junctions.
OPTIMIZATION OF PRESTRESSED CONCRETE BEAMS-student vincenzo robertiVincenzo Roberti
This document summarizes a student's final report on optimizing the design of prestressed concrete beams. The student formulated the problem using nonlinear programming to minimize the cost of the beam based on design variables like section dimensions and amount of prestressing steel. Constraints included practical bounds on dimensions and strength requirements. Standard and idealized beam sections were analyzed. Results found that a double tee section minimized cost and increasing concrete strength reduced cost for T-beams with 7 ksi concrete being optimal. Standard sections analysis confirmed idealized section results. The student concluded the idealized section optimization provided effective guidance to find the lowest cost standard beam section design.
Tc 202-transportation geotechnics and geoecology conferenceOzgur Bezgin
This presentation presents the concept of "Impact Reduction Factor" and the "Bezgin Impact Factor" to estimate vertical impact forces on railways due to track profile variation.
This presentation introduces the concept of "impact reduction factor" and a new method that are both developed by Dr. Niyazi Özgür Bezgin to estimate vertical impact forces on railways due to track stiffness variations.
97th transportation research board meeting presentation-poster session 583Ozgur Bezgin
This presentation introduces the concept of impact reduction factor and a method both developed by Dr. Niyazi Özgür Bezgin that can estimate vertical impact forces on railways due to changes in track profile. The Bezgin Impact Factors KB1 and KB2 are introduced.
Track usually consists of steel rails installed on sleepers/ties and ballast. Sleepers bear the force of the track and act as an elastic medium to absorb blows and vibrations from passing trains. They help maintain the lateral stability, direction, position and gauge of the track. Rails guide conical, flanged train wheels and keep vehicles on the track without active steering, allowing trains to be much longer than road vehicles. Rails must be made of high quality steel to withstand high static and dynamic stresses from heavy loads and lateral forces at curves.
The formula cars need high tire grip on racing challenge by reducing rolling displacement at corner or
double change lands. In this case study, the paper clarifies some issues related to suspension system with
inerter to reduce displacement and rolling angle under impact from road disturbance on Formula SAE
Car. We propose some new designs, which have an advance for suspension system by improving dynamics.
We optimize design of model based on the minimization of cost functions for roll dynamics, by reducing the
displacement transfer and the energy consumed by the inerter. Base on a passive suspension model that we
carried out quarter-car and half-car model for different parameters which show the benefit of the inerter.
The important advantage of the proposed solution is its integration a new mechanism, the inerter, this
system can increase advance in development and have effects on the vehicle dynamics in stability vehicle.
Gears are used to transmit mechanical power from one rotating shaft to another. There are several types of gears that are commonly used including spur gears, helical gears, bevel gears, and worm gears. Spur gears have straight teeth that allow for easy engagement and disengagement. This document discusses the design, specification, and selection of spur gears based on failure due to bending stress using the Lewis equation. It provides information on gear terminology, types of gear trains, tooth systems, force analysis, stresses, selection procedures, and wear failure. Examples are also included to demonstrate how to select suitable gears based on given design parameters and constraints.
This document discusses vibration suppression of a vehicle-bridge interaction system using multiple tuned mass dampers (TMDs). It presents a mathematical model of a system consisting of a vehicle, bridge beam, and three TMDs placed at different locations on the bridge. The model approximates the bridge deflection using the first four mode shapes. Equations of motion are derived for the vehicle, TMDs, and bridge using Lagrange's equations. It is found that placing TMDs at the anti-nodes of the first and second mode shapes is most effective for vibration suppression.
The document discusses spring rates, motion ratios, roll stiffness, and anti-roll bars. It provides equations to calculate spring rates for coil springs and torsion bars based on material properties and geometry. Motion ratio is defined as the displacement ratio between the spring and wheel center, and affects wheel rate. Roll stiffness is determined from individual wheel rates and track width. Asymmetric spring rates and locations are also addressed. Anti-roll bars contribute additional roll stiffness that depends on bar properties and motion ratio.
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Abstract
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for the purpose of analysis. IRC Class AA type of vehicle is simulated on two lanes on the beam of span 31m, having a box type
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Keywords: Dynamic analysis, horizontally curved beam, finite element, moving vehicular moving load, Simply
Supported, Box type, parametric study, L/R ratio
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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.
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1. 5th International Conference
on Road and Rail Infrastructure
CETRA 2018
Niyazi Özgür BEZGIN
Associate Professor
I s t a n b u l U n i v e r s i t y
Proposal of a new analytical method to estimate the
vertical impact forces on railway tracks due to
changes in track profile and track stiffness
2. Content
Introduction to dynamic impact forces on railway tracks
Proposal of a new analytical method that estimates impact forces
and a brief review of previously presented work
Impact forces due to descending and ascending track profiles.
Impact forces due to increasing and decreasing track stiffness.
Conclusions
3. Introduction
Perfectly level running track profile:
Running track profile with irregularities are:
1. Variation of track profile along a length of track.
2. Variation of track stiffness along a length of track.
3. Variation of wheel circularity (wheel flats).
4. Variation in track profile
Variation in track profile generates the difference in the potential
energy of the tributary wheel mass.
5. Variation in track stiffness
Variation in static track deflection generates the difference in the
potential energy of the tributary wheel mass.
6. Variation in wheel circularity
Each of these variations, generate a change in the potential
energy of the tributary mass of the wheel, as the wheel rolls
along the track.
Variation in the abrupt change in wheel diameter generates the
difference in the potential energy of the tributary wheel mass.
9. Multi-body simulation software : They provide engineering
estimates with higher precision and they are useful for design
finalization and assesment of track maintenance.
• Simpack®, Vampire®, Universal Mechanism®, Simulia® and
more…
One may unconditionally yield to their estimates thereby
relinquishing the engineering judgement.
One may lack, the time, tool or the budget for such an analysis.
Can we develop a simple pencil and paper method?
Some advanced analytical estimation methods
10. Potential energy for the tributary wheel mass can develop as a
variation in the track profile, track stiffness or wheel circularity.
Part of this potential energy of the tributary mass releases into
the track to be stored as potential energy of the deformed track.
The stiffness of the track and the wheel, roughness of the track
and/or the wheel and the train speed, influence the generated
impact on the track.
Potential energy of the tributary wheel mass
11. A new concept: Impact reduction factor
This rate of change is embodied in a new concept named the
impact reduction factor (f) (Bezgin, 2017).
14. a
Static wheel force P due to the tributary wheel mass, causes
vertical rail deformation a.
Track stiffness per rail k relates to the force and the
deformation.
𝐤 =
𝐏
𝐚
=
𝐦𝐠
𝐚
Linear-elastic idealization of track stiffness
17. The concept of f and KB,d first presented and published
at:
18. Comparisons of KB,d with some of the existing empirical
equations, presented at TCG 2017 in St. Petersburg
19. KB,d revised and presented and published at 97th. TRB
Meeting in Washington, DC:
Where the theory underlying the equation KB,d was explained
in detail and also notational presentation improved.
30. KB,d and KB,a estimations: An example
Track stiffness per rail is k=43 kN/mm.
The static axle force is Fs=170 kN
The static rail deflection is a= 85 kN÷ 43 kN/mm = 2 mm.
The vertical variation of track profiles are: h=4 mm, h= 8 mm
and h=12 mm.
Therefore h/a values are: 4/2= 2, 8/2= 4 and 12/2= 6.
Rough track lengths are: L=10m, L=25 m and L=70 m.
31. The durations required to traverse (tp) the rough track
lengths (L)
10 25 70
km/h m/s
50 13.9 0.72 1.80 5.04
100 27.8 0.36 0.90 2.52
200 55.6 0.18 0.45 1.26
300 83.3 0.12 0.30 0.84
Train speed
L (m)
tp (s)
34. Variations of KB,d and KB,a for descending and ascending
track conditions
Let us not forget: a = static rail deflection = 2 mm
35. Discussion of results
Track with a high stiffness, amplifies the effect of a profile
variation by increasing h/a, whereas increased static wheel
forces reduce the effect of profile variation by decreasing h/a.
For a track with track stiffness per rail of k, the dynamic impact
force of the wheel at a speed of v relates to h/L.
Estimated impact force values due to ascending and descending
track profiles for a given h/L are different.
For a given track stiffness, train speed and |h/L|, the
descending track profile produces higher impacts compared to
ascending track profiles.
36. Discussion of results
Estimated impact force values due to increasing and decreasing
track profiles are different.
n-fold variation and 1/nth variation in track stiffness produces
different impact values on the track.
Proposed method yielded clear and explicit analytical
equations that relate the dynamic impact forces on railway
tracks to track stiffness, track roughness and train speed.
The first four equations: KB,d, KB,a, KB1, KB2 are proposed by
Bezgin (2017 and 2018) and the fifth equation KB3 is proposed
by Kolukırık and Bezgin (2017)….Session 5.A on May 18th.