Mathematical Modeling of a New Improved Design of a Rail Carriage Suspension System for the Wagons Used in Zimbabwe

2009 ◽  
Vol 62-64 ◽  
pp. 645-654 ◽  
Author(s):  
C. Mbohwa ◽  
J. Agwa-Ejon ◽  
C. Murasiki
Keyword(s):  
Mathematical Modeling ◽  
Shock Absorber ◽  
Ride Comfort ◽  
Suspension System ◽  
Human Comfort ◽  
Research Issues ◽  
Vibration Transmission ◽  
Shock Absorbers ◽  
Improved Design ◽  
Dynamic Attributes

This paper discusses the mathematical modeling of a new improved design of the carriage bogie suspension system with emphasis on design for human comfort. The research mainly covered the shock absorbers with the aim of improving ride comfort at higher speeds. The paper focuses on how to reduce vibration transmission to the carriage while designing a railway bogie suspension damping system that is easier to maintain but does not compromise on quality with particular interest in dynamic attributes of the shock absorber. The principal research issues are introduced and looked at in the modeling and the results so obtained are used to calculate the relative transmissibility in the motion of the carriage.

scholarly journals Contribution to the development of methodology for assessing the impact of bus suspension system on fuel consumption and CO2 emission

2020 ◽  
pp. 168-168
Author(s):  
Dragan Sekulic ◽  
Ivan Ivkovic ◽  
Dusan Mladenovic ◽  
Davor Vujanovic
Keyword(s):  
Fuel Consumption ◽  
Co2 Emission ◽  
Degrees Of Freedom ◽  
Shock Absorber ◽  
Ride Comfort ◽  
Suspension System ◽  
Vertical Acceleration ◽  
Shock Absorbers ◽  
Parameter Values ◽  
The Impact

This paper analyzes the effects of intercity bus suspension system oscillatory parameters on driver's ride comfort and road damage. The analysis has been carried out through simulation by means of validated in-plane bus model with six degrees of freedom excited by real road roughness signal. Low root-mean-square values of the weighted vertical acceleration (less than 0.315 m/s2) have been achieved by shock-absorbers with lower damping coefficient and softer suspension system springs. Low values of dynamic load coefficient provide low shock-absorber damping and softer springs. However, low crest factor values for both axles are accomplished for high shock-absorber damping and softer springs in bus suspension system. Results from this analysis could be used as reference for selecting proper oscillatory parameter values when designing road-friendly bus suspension system which in turn would increase vehicle energy efficiency. Presented methods, results and analyzes are the part of wider methodology for assessing the impact of bus suspension system on fuel consumption and CO2 emission.

Mathematical modeling of elastoplastic deformation of tubular energy-absorbing elements under static and impact loading

2020 ◽  
pp. 78-82
Author(s):  
A.Р. Evdokimov ◽  
A.N. Gromyiko ◽  
A.A. Mironov
Keyword(s):  
Mathematical Modeling ◽  
Impact Loading ◽  
Elastoplastic Deformation ◽  
Shock Absorber ◽  
Analytical Models ◽  
Dynamic Impact ◽  
Shock Absorbers ◽  
Energy Absorbing ◽  
Absorbing Elements

Analytical models of static and dynamic impact elastoplastic deformation of tubular energy-absorbing elements constituting a tubular plastic shock absorber are proposed. The developed models can be used for the calculation and design of these shock absorbers. Keywords static and dynamic elastoplastic deformation, mathematical modeling, tubular energy-absorbing element, tubular plastic shock absorber, impact loading. [email protected]

Performances of Energy-Harvesting Shock Absorbers on Various Types of Vehicles

2015 ◽  
Author(s):  
Sijing Guo ◽  
Lin Xu ◽  
Yilun Liu ◽  
Xuexun Guo ◽  
Lei Zuo
Keyword(s):  
Energy Harvesting ◽  
Vehicle Dynamics ◽  
Degrees Of Freedom ◽  
Large Scale ◽  
Shock Absorber ◽  
Ride Comfort ◽  
Rotational Inertia ◽  
Shock Absorbers ◽  
Regenerative Shock Absorber ◽  
Comprehensive Study

Energy-Harvesting Shock Absorber (EHSA), as a large-scale energy-harvesting mechanism for recovering suspension vibration energy, has been studied for years. A design of the regenerative shock absorber with Mechanical Motion Rectifier (MMR) has been proved to be more reliable and efficient. This paper reports a comprehensive study of the influence of MMR-based Energy-Harvesting Shock Absorber (MMR-EHSA) on vehicle dynamics performances. Models of MMR-EHSA and vehicle with MMR-EHSA with two degrees of freedom are created. Simulations are conducted on five typical vehicles, including passenger car, bus and three types of trucks. The ride characteristics of comfort, road handling and energy recovery are evaluated on these vehicles under various MMR rotational inertia and harvesting damping. The simulation results show that MMR-EHSA is able to improve both the ride comfort and road handling simultaneously under certain conditions over the traditional shock absorbers, which broadens our knowledge of MMR-EHSA’s applicable scenarios.

Use of nonlinear asymmetrical shock absorbers in multi-objective optimization of the suspension system in a variety of road excitations

2016 ◽  
Vol 231 (2) ◽  
pp. 372-387 ◽  
Author(s):  
Abolfazl Seifi ◽  
Reza Hassannejad ◽  
Mohammad Ali Hamed
Keyword(s):  
Degrees Of Freedom ◽  
Ride Comfort ◽  
Low Cost ◽  
Suspension System ◽  
Objective Functions ◽  
Multi Objective Optimization ◽  
Vehicle Handling ◽  
Multi Objective ◽  
Shock Absorbers ◽  
The Impact

In this study, a new method to improve ride comfort, vehicle handling, and workspace was presented in multi-objective optimization using nonlinear asymmetrical dampers. The main aim of this research was to provide suitable passive suspension based on more efficiency and the low cost of the mentioned dampers. Using the model with five degrees of freedom, suspension system parameters were optimized under sinusoidal road excitation. The main functions of the suspension system were chosen as objective functions. In order to better illustrate the impact of each objective functions on the suspension parameters, at first two-objective and finally five-objective were considered in the optimization problem. The obtained results indicated that the optimized viscous coefficients for five-objective optimization lead to 3.58% increase in ride comfort, 0.74% in vehicle handling ability, and 2.20% in workspace changes for the average of forward and rear suspension.

Design and Dynamic Simulation Research of a Bionic Three-Link Tube Shock Absorber

2020 ◽  
Vol 13 ◽  
Author(s):  
Yong Song ◽  
Yue Li ◽  
Zhanlong Li ◽  
Jinyi Lian ◽  
Qinglu Shi ◽  
...  
Keyword(s):  
Dynamic Simulation ◽  
Shock Absorber ◽  
Ride Comfort ◽  
Three Dimensional ◽  
Structure Design ◽  
The Body ◽  
Three Dimensional Modeling ◽  
Shock Absorbers ◽  
Link Mechanism ◽  
Vehicle Suspension System

Background:: Shock absorbers are the main damping component of vehicle suspension system, whose excellent passive characteristics can greatly improve and guarantee the ride comfort and handling stability of vehicles. Therefore, it is of great significance to research and develop a shock absorber with excellent passive characteristics. Objective:: The purpose of this paper is to propose and design a bionic three-link tube shock absorber with good buffering and vibration reduction performance and bionic adaptive characteristics. In addition, the passive characteristics of the purposed shock absorber are studied. Methods:: The bionics idea is applied to the development of vehicle shock absorbers. A three-link mechanism with dampers and springs is abstracted and designed according to the structure and the function of kangaroo legs. A bionic three-link tube shock absorber is constructed based on the traditional tube shock absorber structures and the three-link mechanism. Three-dimensional modeling and three-dimensional dynamic simulation of the shock absorber are carried out by CATIA and ADAMS. Results:: The body acceleration are greatly reduced relative to excitations; the dynamic displacement decreases sharply under greater excitation, but there is slight increase under smaller excitation; the motion function and joint change characteristics of the proposed shock absorber are similar to those of kangaroo legs to a certain degree. Conclusion:: The results show that the structure design of the bionic three-link tube shock absorber is reasonable and workable, the shock absorber presents good buffering and damping performance and some bionic adaptive characteristics, however, there is still room for further optimization of the structure design.

Reducing Vertical and Angular Accelerations With Nonlinear Asymmetrical Shock Absorber in Passenger Vehicles

2013 ◽  
Author(s):  
Marcos Silveira ◽  
Bento R. Pontes ◽  
José M. Balthazar
Keyword(s):  
Shock Absorber ◽  
Ride Comfort ◽  
Nonlinear Characteristics ◽  
Passenger Vehicles ◽  
Car Model ◽  
Shock Absorbers ◽  
Nonlinear Shock ◽  
Angular Oscillations ◽  
Impact Absorption ◽  
Severity Parameter

The behaviour of linear and nonlinear shock absorbers are compared to diminish vertical and angular (pitch) accelerations of passenger vehicles, improving comfort by result. A 4-dof half-car model is used with three configurations of dampers: symmetrical, asymmetrical and front asymmetrical. The analyses use three standard road inputs and include variation of the severity parameter, the asymmetry ratio and the velocity of the vehicle. The comparison shows that the asymmetrical system, with nonlinear characteristics, tends to have a smoother and more progressive behaviour. The results show that the use of the front asymmetrical system diminishes angular oscillations of the vehicle. As lower levels of acceleration are essential for improved ride comfort, the use of asymmetrical systems for vibrations and impact absorption is a superior choice for passenger vehicles.

scholarly journals Experimental Researches on the Dynamic Behavior of the Magnetorheological Damper

2020 ◽  
Author(s):  
Alexandru Dobre
Keyword(s):  
Dynamic Behavior ◽  
Shock Absorber ◽  
Active Suspension ◽  
Suspension System ◽  
Magnetorheological Damper ◽  
Passenger Cars ◽  
Damping Force ◽  
The Road ◽  
Shock Absorbers ◽  
Road Profile

In the context of improving the comfort and dynamics of the vehicle, the suspension system has been continuously developed and improved, especially using magnetorheological (MR) shock absorbers. The development of this technology which is relatively new has not been easy. Thus, the first widespread commercial use of MR fluid in a semi-active suspension system was implemented in passenger cars. The magnetorheological shock absorber can combine the comfort with the dynamic driving, because it allows the damping characteristic to be adapted to the road profile. The main objective of the paper is to analyze the dynamic behavior of the magnetorheological shock absorber in the semi-active suspension. In this sense, the author carried out a set of experimental measurements with a damping test bench, specially built and equipped with modern equipment. The results obtained from the experimental determinations show a significantly improved comfort when using a magnetorheological shock absorber, compared to a classic one, by the fact that the magnetorheological shock absorber allows to modify the damping coefficient according to the road conditions, thus maintaining the permanent contact between the tire and the road due to increased damping force.

scholarly journals Numerical simulation of shock absorbers heat load for semi-active vehicle suspension system

2016 ◽  
Vol 20 (5) ◽  
pp. 1725-1739 ◽  
Author(s):  
Miroslav Demic ◽  
Djordje Diligenski
Keyword(s):  
Dynamic Simulation ◽  
Heat Dissipation ◽  
Shock Absorber ◽  
Suspension System ◽  
Heat Energy ◽  
Vehicle Suspension ◽  
Shock Absorbers ◽  
Simulation Based ◽  
Vehicle Suspension System ◽  
Active Vehicle Suspension System

Dynamic simulation, based on modelling, has a significant role during to the process of vehicle development. It is especially important in the first design stages, when relevant parameters are to be defined. Shock absorber, as an executive part of a semi-active suspension system, is exposed to thermal loads which can lead to its damage and degradation of characteristics. Therefore, this paper attempts to analyze a conversion of mechanical work into heat energy by use of a method of dynamic simulation. The issue of heat dissipation from the shock absorber has not been taken into consideration.

scholarly journals Adjustable Valve Semi-Active Suspension System for Passenger Car

2019 ◽  
Vol 16 (2) ◽  
pp. 6470-6481
Author(s):  
M. R. Ahmed ◽  
A. R. Yusoff ◽  
F. R. M. Romlay
Keyword(s):  
Shock Absorber ◽  
Dynamic Behaviour ◽  
Ride Comfort ◽  
Suspension System ◽  
Whole Body ◽  
Ride Quality ◽  
Adjustable Valve ◽  
Straight Line ◽  
Oil Flow ◽  
Electronically Controllable

The suspension of the car plays a very important role in the safety and the comfort of the vehicle and for absorbing the shock waves and give comfort for the driver and passenger. This paper improves the performance of an automobile suspension system by developing electronically adjustable semi-active shock absorber. This achieved by attaching stepper motor for each shock absorber which helps in adjusting the bleed orifice to a certain position that alternates the hydraulic oil flow in the shock absorber between piston’s chamber during the process of compression and rebound. To evaluate the effect of developed semi-active shock absorber on the dynamic behaviour of the vehicle, several tests were carried out on different types of road condition (bumpy, straight-line and roundabout). These tests were used to evaluate the acceleration and ride quality. There is a great range in response when the bleed orifice is opened reached up to 35% between the stiff and soft setting. The value of root means square acceleration (RMS) was calculated and compared with the standard of human exposure to whole-body vibration, which shows an error of 6% slightly. The result shows the effect of electronically controllable shock absorber on a vehicle’s dynamic behaviour — the advantage of electronics to improve the performance of ride comfort and reduced the harms due to undesired vibration.

A New Analytical Method for Influences of Shock Absorber Rubber Mount on Automotive Ride Comfort

2011 ◽  
Vol 299-300 ◽  
pp. 1221-1226
Author(s):  
Li Jun Zhang ◽  
Hong Liang Liu ◽  
Yue Zhong Li
Keyword(s):  
Shock Absorber ◽  
Ride Comfort ◽  
Great Influence ◽  
Suspension System ◽  
System Model ◽  
Equivalent Model ◽  
Frequency Range ◽  
Stiffness Model ◽  
Time Domains ◽  
Nature Frequency

The rubber mount components in suspension system have great influence on ride comfort of automobile. Based on the complex stiffness model and equivalent model of shock absorber rubber mount, the suspension system model with 2DOF including rubber mount components are established by using virtual coordinate. The influences of the stiffness of rubber mount component on the responses of suspension are analyzed in frequency and time domains. The results show that proper stiffness of rubber mount can decrease the acceleration of body by about 20% and dynamic load of tire by about 30% in the frequency range from 5 to 12 Hz compared with that without rubber mount. In addition, the stiffness of rubber mount component leads to lag acceleration of body and higher nature frequency of wheel.

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