scholarly journals Research on Damping Characteristics of Interconnected Hydropneumatic Suspension considering the Effects of Hose and Check Valve

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Hongmin Zhang ◽  
Xin Fang
Keyword(s):  
Numerical Simulation ◽  
Energy Method ◽  
Damping Ratio ◽  
Check Valve ◽  
Nonlinear Stiffness ◽  
Calculation Formula ◽  
Damping Force ◽  
Damping Characteristics ◽  
Simulation Results ◽  
Stiffness And Damping

The interconnected hydropneumatic suspension (ICHPS) has not only the nonlinear stiffness and damping of the independent hydropneumatic suspension (IDHPS) but also antiroll and antipitch functions. The existing analysis of hydropneumatic suspension damping mainly focuses on the orifice and check valve in the suspension cylinder. In this study, the calculation formula of the damping force of ICHPS is established, and the numerical simulation results show that the damping characteristics of the hydraulic hose cannot be ignored. The influence of check valve and hose on the damping characteristics is analyzed. Through the equivalent energy method, the equivalent compression damping ratio and the equivalent recovery damping ratio of the ICHPS are established. It is pointed out that when designing the damping characteristics of the ICHPS, it is necessary to select the orifices, check valves, and hose damping reasonably to make the damping characteristics get the best match.

scholarly journals A High-Efficiency Energy Harvesting By Using Hydraulic Electromagnetic Regenerative Shock Absorber

2020 ◽  
Author(s):  
Muhammad Yousaf Iqbal ◽  
Zhifei Wu ◽  
Khalid Mahmood
Keyword(s):  
Mathematical Model ◽  
Energy Harvesting ◽  
Shock Absorber ◽  
Mechanical Energy ◽  
Excitation Frequency ◽  
National Standard ◽  
Damping Force ◽  
Damping Characteristics ◽  
Simulation Results ◽  
Regenerative Shock Absorber

Abstract This article intends a hybrid energy harvesting shock absorber design which comprehends energy harvesting of automobile suspension vibration dissipation. A mathematical model of the energy harvesting prototype is established, and simulation results show that the dissipation energy can be recovered by varying the feed module, thereby got the damping forces ratio at different compression and extension stroke. The energy conversion from hydraulic energy to mechanical energy mainly then mechanical energy converted into electrical energy furthermore we can rechange our battery from this recovered energy. The advanced mathematical model and prototype proposed maximum ride comfort meanwhile recovered the suspension energy and fuel saving. This article shows the simulation results verifying it with prototype test results. The damping force of expansion stroke is higher than the damping force of compression stroke. The damping characteristics curves and speed characteristics curves verify the validity by simulation and prototyping damper at different amplitudes of off-road vehicles. The Hydraulic Electromagnetic Regenerative Shock Absorber (HESA) prototype characteristic is tested in which 65 watts recovered energy at 1.67 Hz excitation frequency. So, 14.65% maximum energy recovery efficiency got at 20 mm rod diameter and 8 cc/rev motor displacement. The damping characteristics of the HESA prototype examined and it has ideal performance as the standard requirements of the National Standard QC/T 491–1999.

scholarly journals ENHANCED DAMPING CHARACTERISTICS OF TIMOSHENKO BEAM ON ELASTIC AND METAMATERIAL FOUNDATIONS

2020 ◽  
Vol 14 (1) ◽  
pp. 52-62
Author(s):  
A. O. Oyelade ◽  
O. M. Sadiq
Keyword(s):  
Timoshenko Beam ◽  
Damping Ratio ◽  
Reference Beam ◽  
Negative Stiffness ◽  
Flexural Wave ◽  
Flexural Waves ◽  
Static Stiffness ◽  
Damping Characteristics ◽  
Simulation Results ◽  
Flexural Wave Propagation

An analytical model is developed for the flexural wave propagation of a continuous Timoshenko beam resting on elastic and metamaterial foundations. The metamaterial foundation consists of positive and negative springs with a damper. This added negative stiffness component is constructed in such a way to provide the same static stiffness and the same damping component with the equivalent reference beam on elastic foundation. Numerical examples are used to investigate the effect of the shear on wavenumber and damping for beam with elastic and metamaterial foundations. The effects of engineering safety, damping coefficient and resonating mass on the dissipative property of the beam is investigated analytically. The simulation results provide indication of an enhanced damping characteristics for the damping ratio of the flexural waves propagating within the beam.

scholarly journals Analysis of Damping Characteristics of a Hydraulic Shock Absorber

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Zhifei Wu ◽  
Guangzhao Xu ◽  
Hongwei Yang ◽  
Mingjie Li
Keyword(s):  
Shock Absorber ◽  
Check Valve ◽  
Line Length ◽  
Hydraulic Shock ◽  
Hydraulic Motor ◽  
Damping Force ◽  
Unidirectional Flow ◽  
Damping Characteristics ◽  
Hydraulic Shock Absorber ◽  
Inner Diameter

In the present study, a hydraulic shock absorber is proposed. Since the damper is mainly used in suspension energy recovery system, the damping characteristics of the damper under no-load state are studied in this paper. Structural design is conducted so that the unidirectional flow of the oil drives the hydraulic motor to generate electricity. Meanwhile, an asymmetrical extension/compression damping force is obtained. A mathematical model of the shock absorber is established, and the main characteristics of the inherent damping force are obtained. Based on the established model, effects of the accumulator volume, accumulator preinflation pressure, hydraulic motor displacement, check valve inner diameter, and spring stiffness, hydraulic line length and inner diameter on the indicator characteristics are analyzed. Moreover, a series of experiments are conducted on the designed damper to evaluate the characteristics of the inherent damping force and analyze the effect of the accumulator volume and preinflation pressure on the damping characteristics.

Performance analysis of a new hydropneumatic inerter-based suspension system with semi-active control effect

2020 ◽  
Vol 234 (7) ◽  
pp. 1883-1896
Author(s):  
Lin Yang ◽  
Ruochen Wang ◽  
Xiangpeng Meng ◽  
Zeyu Sun ◽  
Wei Liu ◽  
...  
Keyword(s):  
Active Control ◽  
Network Theory ◽  
Suspension System ◽  
Bench Test ◽  
Control Effect ◽  
Damping Characteristics ◽  
Control Comparison ◽  
Simulation Results ◽  
Stiffness And Damping ◽  
The Relationship

This paper develops a hydropneumatic inerter-based suspension system theoretical model to analyze its performance, based on the mechanical network theory of inerter and semi-active control. Comparison of the stiffness and damping characteristics among a passive hydropneumatic suspension system, semi-active hydropneumatic suspension system based on skyhook control, and hydropneumatic inerter-based suspension system is conducted. Moreover, the relationship between the internal coefficient of the inerter and the damping coefficient of the hydropneumatic suspension is investigated. The simulation results of the flow–volume curves of the hydropneumatic inerter-based suspension system are close to those of the semi-active hydropneumatic suspension system based on skyhook control. Furthermore, the performance of a quarter vehicle model with the hydropneumatic inerter-based suspension system is analyzed and compared to that with the semi-active hydropneumatic suspension system based on skyhook control. The simulation results show that the performance of the hydropneumatic inerter-based suspension system is as good as that of the semi-active hydropneumatic suspension system based on skyhook control, which means that the hydropneumatic inerter-based suspension system can achieve similar performance for semi-active control suspension. Finally, a prototype is developed, and a comparative bench test is carried out to verify the accuracy of the simulations. In addition, the hydropneumatic inerter-based suspension system can achieve semi-active control performance without additional hardware or energy loss.

Experimental Evaluation of Magnetorheological Damper Characteristics for Vibration Analysis

2018 ◽  
Vol 10 (1) ◽  
Author(s):  
S. Siva Kumar ◽  
K.S. Raj Kumar ◽  
Navaneet Kumar
Keyword(s):  
Vibration Isolation ◽  
Mr Damper ◽  
Magnetorheological Damper ◽  
Damping Force ◽  
Mr Fluid ◽  
Damping Characteristics ◽  
Fluid Damper ◽  
Mr Fluid Damper ◽  
Stiffness And Damping ◽  
Theoretical Results

Magnetorheological (MR) fluid damper has been designed, fabricated and tested to find the stiffness and damping characteristics. Experimentally the MR damper has been tested to analyse the behaviour of MR fluid as well as to obtain the stiffness for varying magnetic field. MR damper mathematical model has been developed for evaluating dynamic response for experimentally obtained parameters. The experimental results show that the increase of applied electric current in the MR damper, the damping force will increase remarkably up to the saturation value of current. The numerical simulation results that stiffness of the MR damper can be varied with the current value and increase the damping forces with the reduced amplitude of excitation. Experimental and theoretical results of the MR damper characteristics demonstrate that the developed MR damper can be used for vibration isolation and suppression.

Study on Impacting Characteristics of a Metro Vehicle

2010 ◽  
Vol 139-141 ◽  
pp. 2648-2652
Author(s):  
Suo Huai Zhang ◽  
Ming Wei Wan
Keyword(s):  
Numerical Simulation ◽  
Energy Dissipation ◽  
Friction Force ◽  
Nonlinear Stiffness ◽  
Stiffness And Damping

In order to analyze impacting characteristics of a metro vehicle, the impacting governing Eq. is established, in which, nonlinear stiffness and damping of a buffer, friction force between rail and wheel of the vehicles is considered. In terms of testing results, nonlinear stiffness and damping of the buffers is simulated. By numerical simulation, it is found that when moving trainset impacts standing trainset, because the impacting force, stroke of buffers located in impacting interface is the maximum, the capacity of the buffers must be large enough to avoid rigid impact; when trainset with different number vehicles impacts each other, the maximum impacting force is not only different from each other, but the stroke and energy dissipation of the buffers is also different; the capacity of buffers far from impacting interface may be small.

SEMI-ACTIVE CONTROL FOR VIBRATION SUPPRESSION IN A SYSTEM SUBJECTED TO UNKNOWN DISTURBANCES

1994 ◽  
Vol 04 (04) ◽  
pp. 379-393
Author(s):  
G. LEITMANN
Keyword(s):  
Vibration Suppression ◽  
Electrorheological Fluid ◽  
Electrorheological Fluids ◽  
Joint Control ◽  
Damping Characteristics ◽  
Control Schemes ◽  
Unknown Disturbances ◽  
Simulation Results ◽  
Stiffness And Damping ◽  
External Stimuli

With the advent of materials, such as electrorheological fluids, whose material properties can be altered rapidly by means of external stimuli, employing such materials as actuators for the controlled attenuation of undesirable vibrations is now possible. Such control schemes are dubbed semi-active in that they attenuate vibrations whether applied actively or passively. We investigate various such control schemes, allowing for both separate and joint control of the stiffness and damping characteristics of the material. Simulation results are given for the case of an electrorheological fluid.

scholarly journals Dynamics Simulation of Stirling Engine for Solar Energy Based on the Time-Varying Support Stiffness

2014 ◽  
Vol 8 (1) ◽  
pp. 710-715
Author(s):  
Junzhou Huo ◽  
Hanyang Wu ◽  
Jing Chen
Keyword(s):  
Damping Ratio ◽  
Simulation Method ◽  
Stirling Engine ◽  
Output Shaft ◽  
Dynamics Simulation ◽  
Time Varying ◽  
Vibration Displacement ◽  
Constant Stiffness ◽  
Simulation Results ◽  
Stiffness And Damping

In order to simulate the Stirling engine more easily, the stiffness and damping ratio of the crankshaft bearing are assumed to be steady-state in the research before, but this assumption is contrary to the real condition. Therefore, in this paper, a time-varying stiffness and damping ratio of the crankshaft bearing simulation method has been proposed. Compared with the simulation results of the crankshaft bearings with constant stiffness, the speed fluctuation coefficient of output shaft and crankshaft in time-varying stiffness model is increased by 10%, 24.6% and 13.7%; the vibration displacement of the center mass of output shaft is decreased by 3.0%; the average dynamic load on airframe is increased by 47.9%. From the simulation results, it is found that the time-varying stiffness and damping ratio of the crankshaft bearing is significant to the characteristics of the Stirling engine dynamic response.

Finite Element Modeling and Analysis of Friction-Wedge Dampers During Suspension Pitch Modes

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Y. Q. Sun ◽  
C. Cole
Keyword(s):  
Finite Element ◽  
Element Model ◽  
Friction Damping ◽  
Damping Force ◽  
Modeling And Analysis ◽  
Damping Characteristics ◽  
Wedge Shape ◽  
Dimensional Finite Element ◽  
Simulation Results ◽  
Elasticity Effects

A two-dimensional finite element model has been developed to investigate the friction damping characteristics of suspensions with so-called “constant-damping” friction wedges widely used in three-piece bogie wagons in Australia. The model was used to simulate the suspension during pitch modes. The simulation results show that the friction damping force in the suspension pitch modes is dependent on the friction conditions on the wedge contact surfaces, wagon speed, and the wedge shape and elasticity effects including the stuck state. The suspension pitch movements of a three-piece bogie with dry friction wedges can cause wedge rotation and partial separation of wedge contacting surfaces, which seriously affects the wedge friction damping effectiveness. The curved shape of wedge angular surface can significantly improve the friction damping characteristics of three-piece bogie suspensions.

scholarly journals Displacement Transmissibility Characteristics of Harmonically Base Excited Damper Isolators with Mixed Viscous Damping

2013 ◽  
Vol 20 (5) ◽  
pp. 921-931 ◽  
Author(s):  
Xiaojuan Sun ◽  
Jianrun Zhang
Keyword(s):  
Damping Ratio ◽  
Harmonic Balance Method ◽  
Nonlinear Damping ◽  
Viscous Damping ◽  
Damping Force ◽  
Response Characteristics ◽  
Damping Characteristics ◽  
Linear Damping ◽  
Frequency Ratios ◽  
Good Agreement

The viscous damping force in the mixed form asfd(x˙)=c1x˙+c2|x˙|x˙can well describe damping characteristics of isolators and dampers in many cases. In this paper, performance characteristics of single-degree-of-freedom (SDOF) linear-stiffness isolators with mixed and piecewise mixed viscous damping are analytically examined under harmonic base excitation. Based on the first-order harmonic balance method (HBM), both relative and absolute displacement transmissibility expressions with the equivalent linear damping coefficient (ELDC) are given. And the analytical calculations show good agreement with the numerical results. Also, the influence of nonlinear damping on the response characteristics is investigated by comparing the transmissibility of linear and nonlinear systems. The resonant frequency always shifts to a lower value as the nonlinear damping component of the forcefd(x˙)=c1x˙+c2|x˙|x˙becomes stronger, and when the damping ratio in the corresponding linear model is relatively high, the relative transmissibility decreases at frequencies higher than the resonance frequency of the corresponding linear damping system and the absolute one increases for the frequency ratios above2. Finally, the displacement transmissibility of a nonlinear isolator with piecewise mixed viscous damping is discussed and the process shows research similarity with the non-piecewise case.

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