scholarly journals Investigation of the suspension design and ride comfort of an electric mini off-road vehicle

2019 ◽  
Vol 11 (1) ◽  
pp. 168781401882335 ◽  
Author(s):  
Bin Yu ◽  
Zhice Wang ◽  
Guoye Wang ◽  
Jianzhu Zhao ◽  
Liyang Zhou ◽  
...  
Keyword(s):  
Shock Absorber ◽  
Natural Frequencies ◽  
Ride Comfort ◽  
Piecewise Linear ◽  
Damping Ratio ◽  
Road Vehicle ◽  
Pulse Input ◽  
Response Characteristics ◽  
Quarter Car Model ◽  
Damping Characteristics

In view of the little research that has been conducted on the ride comfort of mini vehicles, an electric mini off-road vehicle was designed in this study and a 2 degree-of-freedom quarter car model was established to investigate the ride comfortability. The amplitude-frequency and vibration response characteristics of the suspension were analyzed with the natural frequencies of the front and rear suspensions selected in accordance with the required driving performance. A comprehensive objective function with respect to the safety and comfortability was established, and the damping ratio of the suspension was determined. The damping characteristics of the shock absorber were analyzed to derive an adjustment rule of the suspension damping ratio. The piecewise linear speed characteristics of the shock absorber were subsequently obtained, and suspension-parameter identification and ride comfort tests were conducted. The test results showed that the natural frequencies and damping ratios of the front and rear suspensions were 1.676 and 1.922 Hz, and 0.225 and 0.242, respectively. The results of a pulse input test and D-level road random running test also demonstrated the safety and good ride comfortability of the vehicle.

Variation in Automotive Shock Absorber Damping Characteristics & amp; Their Effects on Ride Comfort Attribute and Vehicle Yaw Response

2021 ◽  
Author(s):  
Satyaranjan Sahoo ◽  
Eric Pranesh De Reuben ◽  
Deepak BAKSHI ◽  
Hari Krishnan ◽  
Amardeep Singh
Keyword(s):  
Shock Absorber ◽  
Ride Comfort ◽  
Damping Characteristics

scholarly journals Experimentally validated dynamic results of a relaxation-type quarter car suspension with an adjustable damper

2017 ◽  
Vol 36 (2) ◽  
pp. 148-159 ◽  
Author(s):  
AN Thite ◽  
F Coleman ◽  
M Doody ◽  
N Fisher
Keyword(s):  
Shock Absorber ◽  
Ride Comfort ◽  
Damping Ratio ◽  
Closed Form Solution ◽  
Nonlinear Function ◽  
Frequency Domain Analysis ◽  
Form Solution ◽  
Damping Coefficient ◽  
Design Stage ◽  
Quarter Car

Models of varying degree of sophistication are used in vehicle dynamic studies. For ride comfort, Kelvin–Voigt arrangement is preferred and for impact harshness analysis, a relaxation-type suspension model, Zener or Maxwell type is used. The nonconsideration of relaxation-type models in ride comfort studies can result in significant errors for frequencies below ∼30 Hz. The object of the paper is to show the influence of the series stiffness on the effective suspension damping both experimentally and numerically. A frequency domain analysis of two-degree of freedom Zener quarter car model is performed to find the complex relation between effective damping coefficient and the limiting value of damping ratio for a given series stiffness. The nonlinear relation between shock absorber damping and the natural frequencies is clearly illustrated. A novel four-post rig set-up is used to validate the results by measuring transmissibilities, giving damping ratios for varying shock absorber settings. A closed form solution, based on a simplified partial model, of optimal damping coefficient, which is a nonlinear function of stiffnesses, shows good agreement with numerical simulations of the complete system. The nonlinearities in shock absorbers also influence the outcome. These findings can be a great value at early design stage.

Experimental and Numerical Investigation of Vibration Damping Using a Thin Layer Coating

2017 ◽  
Author(s):  
Imran Aziz ◽  
Sajjad Hussain ◽  
Wasim Tarar ◽  
Imran Akhtar
Keyword(s):  
Nickel Alloy ◽  
High Cycle Fatigue ◽  
Natural Frequencies ◽  
Damping Ratio ◽  
Rotating Machinery ◽  
Forced Response ◽  
Cycle Fatigue ◽  
Damping Characteristics ◽  
At Resonance ◽  
Vibration Shaker

High cycle fatigue (HCF) is the main cause of failure in rotating machinery especially in aircraft engines which results in the loss of human life as well as billions of dollars. More than 60 percent of aircraft accidents are related to High cycle fatigue. Major reason for HCF is vibratory stresses induced in the blades at resonance. Damping is needed to avoid vibratory stresses to reach the failure level. High speed rotating machinery has to pass through the resonance in order to reach the operational speed and chances of failure are high at resonance level. It is therefore required to suppress the vibrations at resonance level to avoid any damage to the structure. Application of coating to suppress vibrations is a current area of research. Various types of coatings have been studied recently. This includes plasma graded coatings, viscoelastic dampers, piezoelectric material damping, and magnetomechanical damping. In this research, the phenomenon of damping using a coating of nickel alloy on a steel beam is studied experimentally and numerically to reduce vibratory stresses by enhancing damping characteristics to avoid aircraft engine and rotating machinery failure. For this purpose, uncoated and nickel alloy coated steel beams are fabricated. The coating procedure was performed using plasma arc method. The beams were then mounted in a cantilevered position and bump and vibration shaker tests were conducted to determine the natural frequencies and mode shapes. One of the most important parameter to measure the damping of a system is the damping ratio. In order to determine the damping ratio, vibration analyzer mode was adjusted in time domain and beam was excited by using a hammer. The vibration analyzer showed the vibration decay as a function of time. Using that decay, damping ratio was calculated by using logarithmic decrement method. In order to investigate and compare the damping characteristics of un-coated and coated beams, forced response method was employed. In this method, beams were excited at 1st and 2nd bending mode natural frequencies using vibration shaker. Results were very encouraging and showed a significant improvement in damping characteristics. The experimental results were then endorsed by numerical results which were achieved by performing modal and forced response analysis using finite element analysis techniques.

Investigation of Control Algorithms for Semi-Active Suspension Systems Based on a Full Vehicle Model

2011 ◽  
Author(s):  
M. A. Ajaj ◽  
A. M. Sharaf ◽  
S. A. Hegazy ◽  
Y. H. Hossamel-deen
Keyword(s):  
Control Algorithm ◽  
Shock Absorber ◽  
Ride Comfort ◽  
Active Suspension ◽  
Control Algorithms ◽  
Suspension Systems ◽  
Full Vehicle ◽  
Damping Characteristics ◽  
Active Suspension Systems ◽  
Suspension Control

This paper presents a comprehensive investigation of automotive semi-active suspension control algorithms and compares their characteristics in terms of ride comfort and tire-road holding ability. Particular attention has been paid to the semi-active suspension systems fitted with a shock absorber of dual damping characteristics. Different mathematical models are presented to investigate the ride response considering both simplified and complex vehicle models. Numerical simulation has been carried out through the MATLAB/SIMULINK environment which aids the future development of controllable suspension systems to improve vehicle ride comfort. The results show a considerable improvement of the vehicle ride response using different schemes of semi-active suspension system in particular the modified groundhook control algorithm.

Semi-Active Damping for Off-Road Bicycle Suspension: An Experimental Study

2018 ◽  
Author(s):  
R. Scott Pierce ◽  
Caleb Whitener ◽  
Sudhir Kaul
Keyword(s):  
Shock Absorber ◽  
Ride Comfort ◽  
Mr Damper ◽  
Power Input ◽  
Rear Wheel ◽  
Active Damping ◽  
Suspension System ◽  
Magnetorheological Damper ◽  
Mountain Bike ◽  
Damping Characteristics

This paper presents experimental results from the testing of a semi-active damping system in an off-road bicycle (bike). Magnetorheological dampers are being increasingly used in automotive applications to enhance damping capability of a suspension system or to mitigate the trade-off between ride comfort and handling. A magnetorheological (MR) damper requires a relatively low amount of energy to control damping characteristics, and behaves as a passive damper in the absence of any power input. This study investigates the use of a semi-active magnetorheological damper for the rear suspension of a mountain bike. The performance of this damper has been compared to the current shock absorber on the bike. All testing has been performed on a shaker table and the performance of the damper has been evaluated by comparing the input acceleration at the hub of the rear wheel to the acceleration at the seat of the bike. The main aim of this study is to investigate the viability of using an MR damper in a mountain bike suspension system. Test results indicate that the performance of the semi-active MR damper is comparable to the current shock absorber. Furthermore, the MR damper lends itself to hands-off control that will be investigated in a future study. Therefore, it can be concluded from preliminary testing that an MR damper can be used in a mountain bike to effectively control damping.

Damping Characteristics of a Hydraulic Electric Rectifier Shock Absorber and its Effect on Vehicle Dynamics

2015 ◽  
Author(s):  
Lin Xu ◽  
Yilun Liu ◽  
Sijing Guo ◽  
Xuexun Guo ◽  
Lei Zuo
Keyword(s):  
Vehicle Dynamics ◽  
Shock Absorber ◽  
Ride Comfort ◽  
Dynamic Performance ◽  
Nonlinear Damping ◽  
Shock Absorbers ◽  
Damping Characteristics ◽  
Electromagnetic Shock ◽  
Oil Shock ◽  
Regenerative Shock Absorber

Many energy-harvesting shock absorbers have been proposed in recent years, the most popular design is the electromagnetic harvester including linear electromagnetic shock absorbers, rotational electromagnetic shock absorbers, the mechanical motion rectifier (MMR), and the hydraulic-electromagnetic energy-regenerative shock absorber (HESA). With different energy converting mechanisms, the complicated effects of the inertia and nonlinear damping behaviors will greatly influence the vehicle dynamic performance such as the ride comfort and road handling. In this paper, we will theoretically analyze the dynamics of the suspension system with the HESA and give a guide for the HESA design. Then a simulation model of the HESA is built in AMESim to make comparison studies on the different vehicle dynamics caused by the nonlinear damping behaviors of the HESA. The advantages of HESA in terms of ride comfort and road handling will be evaluated in comparison with the similar design without accumulators and the traditional oil shock absorbers.

scholarly journals Hybrid sensor network control of vehicle ride comfort, handling, and safety with semi-active charging suspension

2020 ◽  
Vol 16 (2) ◽  
pp. 155014772090458
Author(s):  
Shaoyi Bei ◽  
Chen Huang ◽  
Bo Li ◽  
Zhiyu Zhang
Keyword(s):  
Sensor Network ◽  
Shock Absorber ◽  
Ride Comfort ◽  
Steering System ◽  
Network Control ◽  
Hybrid Network ◽  
Driving Safety ◽  
Negative Effects ◽  
Pulse Input ◽  
Stable Domain

Semi-active charging suspension has been the highlight in the research of ride comfort, handling, and safety of road vehicles in real time. Adjustable damping shock absorber is the key part of semi-active suspension. Many studies are focused on the control and impacts of automotive ride comfort. However, few of them are about the relationship among the damping of adjustable damping shock absorber, handling stability, and safety. In this article, a full car model based on multi-body dynamics was built, including the steering system, front and rear suspensions, tire, driving controller, and road. And the model was verified by tests. Based on the co-simulation, a controller was built based on hybrid sensor network control. The hybrid network control principle was switched among comfort controller, stability controller, and safety controller, in accordance with working conditions. The design effectively improved ride comfort, handling stability, and driving safety. Finally, a rapid control prototype was built based on dSPACE to conduct a real vehicle test. By comparison of the time response diagram, the results on pulse input and S-shaped road indicate that handling stability and driving safety enter into the stable domain and negative effects are successfully suppressed.

Vehicle Ride Comfort Simulation under Pulse Road Surface Based on Multi-Body Dynamics

2011 ◽  
Vol 48-49 ◽  
pp. 1341-1344
Author(s):  
Feng Yan Yi ◽  
Chang Feng Zhou
Keyword(s):  
Shock Absorber ◽  
Ride Comfort ◽  
Road Surface ◽  
Beam Model ◽  
Two Dimensional ◽  
Vehicle Model ◽  
Response Characteristics ◽  
Adams Software ◽  
Body Dynamics ◽  
Multi Body

The shock absorber model and front beam model of a domestic car are built using UG according to the existing two-dimensional drawings. And they are assembled together with the rear beam model, steering knuckles model and arm model. The ADAMS software is used to build up an assembled vehicle model, which includes front and rear suspensions, chassis, steering, tires subsystems and so on. Response characteristics of vehicle ride comfort under pulse road surface are studied through simulation.

Analysis of MR Damper Based on Finite Element Approach

2014 ◽  
Vol 592-594 ◽  
pp. 2006-2010 ◽  
Author(s):  
K. Hemanth ◽  
A. Ganesha ◽  
Hemantha Kumar ◽  
K.V. Gangadharan
Keyword(s):  
Shock Absorber ◽  
Mr Damper ◽  
Active System ◽  
Vehicle Suspensions ◽  
Quarter Car Model ◽  
Damping Characteristics ◽  
Simulink Simulation ◽  
Optimal Current ◽  
Element Approach ◽  
Magneto Rheological

A magneto rheological damper is a damper filled with magneto rheological fluid, which is controlled by a magnetic field. This allows the damping characteristics of the shock absorber to be continuously controlled by varying the force of the electromagnet. This type of shock absorber has several applications, most notably in semi-active vehicle suspensions which may adapt to road conditions, as they are monitored through sensors in the vehicle. This paper presents magnetic saturation analysis of non-parametric model of magnetorheological (MR) damper using ANSYS for improvement of the higher force with optimal current and MATLAB/Simulink simulation for quarter car model equipped with MR damper to conduct dynamic studies of the system using skyhook controller and comparative study for passive and semi-active system.

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