Effect of air chamber and oil properties on damping characteristics of single-tube pneumatic shock absorber

2018 ◽  
Vol 9 (1) ◽  
pp. 27-37 ◽  
Author(s):  
Hongtuo Liu ◽  
Fangwei Xie ◽  
Kai Zhang ◽  
Xinxing Zhang ◽  
Jin Zhang ◽  
...  
Keyword(s):  
Shock Absorber ◽  
Initial Pressure ◽  
Structure Design ◽  
Vehicle Suspension ◽  
Damping Force ◽  
Content Type ◽  
Single Tube ◽  
Damping Characteristics ◽  
Air Chamber ◽  
Pneumatic Shock

Purpose The shock absorber is an important component of vehicle suspension that attenuates the vehicle vibration. Its running state directly affects the performance of the vehicle suspension. The purpose of this paper is to quantitatively study the relationship between damping characteristics and air chamber and oil properties in single-tube pneumatic shock absorber. Design/methodology/approach Combined with the principle of fluid dynamics and hydraulic transmission technology, the rebound stroke and compression stroke mathematical models, and damping characteristics simulation model are established to investigate the effect of the air chamber and oil property on damping characteristics. Findings Research results show that the initial pressure of the air chamber is the key parameter which influences the damping characteristics of the shock absorber. The change of the initial pressure has more impact on damping force, and less impact on the speed characteristic; the initial volume of the air chamber almost has no effect on the damping characteristics. The density and viscosity of the oil have certain influence on the damping characteristics. Therefore, selecting suitable damping oil is very important. Originality/value Using Matlab/Simulink software to build simulation models, its results are very accurate. The conclusions can provide a theoretical reference for the structure design of a single-tube pneumatic shock absorber.

A New Kind of Semi-Active Suspension Magnetorheological Fluid Shock Absorber Damping Force Model

2012 ◽  
Vol 549 ◽  
pp. 856-860
Author(s):  
Peng Sun ◽  
Jian Feng Wang ◽  
Feng Feng
Keyword(s):  
Shock Absorber ◽  
Dynamic Performance ◽  
Vehicle Suspension ◽  
Force Model ◽  
Polarization Current ◽  
Simulation Test ◽  
Damping Force ◽  
Performance Simulation ◽  
Damping Characteristics ◽  
Theory Formula

Based on the damping characteristics, design a kind of magnetic fluid shock absorber, and the damping force theory formula, derived from the damping force of the formula can be that, according to the design of shock absorber, in the vehicle suspension on the dynamic performance simulation test for the damping-displacement characteristic and speed characteristics is verified by experiments, the proof is in the formula of the damping force of the damping force and the polarization current into nonlinear (secondary) relationship is reasonable, to design the actual shock absorber to really have a certain reference value.Intorduction

Fluid flow modeling of a four-stage damping adjustable shock absorber and its experimental research

2018 ◽  
Vol 9 (1) ◽  
pp. 17-26
Author(s):  
Erming Ding ◽  
Fangwei Xie ◽  
Heng Dai ◽  
Qingsong Gao ◽  
Jin Zhang ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Shock Absorber ◽  
Ride Comfort ◽  
Vehicle Suspension ◽  
Flow Modeling ◽  
Damping Force ◽  
Maximum Displacement ◽  
Content Type ◽  
Indicator Diagram ◽  
Fluid Flow Modeling

Purpose In order to improve the ride comfort of vehicle suspension, this paper first proposed a shock absorber with four-stage adjustable damping forces. The purpose of this paper is to validate its modeling and characteristics, indicator diagrams and velocity diagrams, which are the main research points. Design/methodology/approach In order to validate the fluid flow modeling, a series of mathematical modeling is established and solved by using Matlab/Simulink. An experiment rig based on electro-hydraulic loading servo system is designed to test the prototype. Finally, indicator diagram and velocity diagram are obtained and compared both in simulation and experiments. Findings Results indicate that at the same damping position, damping force will increase with the rise of rod’s velocity: if the rod’s velocity is fixed, the damping force changes apparently by altering the damping position. The shock absorber is softest at damping position 1, and it is hardest at damping position 4; although there is no any badly empty stroke and skewness in indicator diagram by simulation, a temporary empty stroke happens at maximum displacement of piston rob, both in rebound and compression strokes. Research limitations/implications Compared with results of the simulation and experiments, the design of a four-stage damping adjustable shock absorber (FDASA) is validated correctly in application, and may improve the overall dynamic performance of vehicle. Originality/value This paper is mainly focused on the design and testing of an FDASA, which may obtain four-stages damping characteristics, that totally has a vital importance to improve the performance of vehicle suspension.

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 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.

Design and Drop Test of Aircraft Landing Gear’s Shock Absorber Based on Magnetorheological Damper

2014 ◽  
Vol 665 ◽  
pp. 601-606
Author(s):  
Xiao Chuan Liu ◽  
Shi Xing Zhu ◽  
Yong Gang Yang
Keyword(s):  
Shock Absorber ◽  
Magnetic Circuit ◽  
Mr Damper ◽  
Magnetorheological Damper ◽  
Damping Force ◽  
Damping Characteristics ◽  
Aircraft Landing ◽  
Piston Displacement ◽  
Drop Tests ◽  
Better Than

The structure of a shock absorber based on magnetorheological (MR) damper with a metering pin is proposed, and structure of the magnetic circuit of MR damper is optimized. By drop tests, the damping characteristics of the shock absorber and damping effect are tested. The experimental results show that the shock absorber has the characteristic of a wide damping force adjustment range and lower energy dissipation. The maximum vertical load and shock absorber piston displacement can be changed at same drop height by changing the current. It has also been proved that shock absorber based on MR damper is better than conventional oleo-pneumatic shock absorber on adjustment of damping force.

scholarly journals Research of the elastic characteristics of the new hydropneumatic shock absorber

2020 ◽  
Vol 17 (2) ◽  
pp. 187-194
Author(s):  
S. V. Repin ◽  
◽  
V. N. Dobromirov ◽  
D. S. Orlov ◽  
A. V. Andronov ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Shock Absorber ◽  
Theoretical Modeling ◽  
Damping Characteristics ◽  
Pneumatic Shock ◽  
Elastic Characteristics

The article is devoted to research on ensuring smooth running of vehicles, and specifically, the theoretical modeling of the damping characteristics of a new design of hydro-pneumatic shock absorber. There has been developed a mathematical model describing the characteristics implemented in MathCad. The influence of various factors on the parameters of the characteristics is studied.

scholarly journals Method for calculating the speed characteristicsof a single-tube shock absorber

2020 ◽  
Vol 17 (2) ◽  
pp. 168-172
Author(s):  
A. M. Voytko ◽  
Keyword(s):  
Shock Absorber ◽  
Operating Conditions ◽  
Hydraulic Systems ◽  
Single Tube ◽  
Basic Approaches ◽  
Urban Conditions ◽  
Pneumatic Shock

The article describes a method for calculating the speed characteristics of a single-tube hydro-pneumatic shock absorber developed by the author based on the use of basic approaches to the calculation of damping hydraulic systems. A regressive type of characteristic is substantiated in relation to the operating conditions of a specialized vehicle in urban conditions. There has been performed calculation and analysis of the speed characteristics of the hydro-pneumatic shock absorber proposed for use on Ford Transit ambulances.

Mathematical modelling and experimental validation of mono-tube shock absorber

2016 ◽  
Vol 13 (4) ◽  
pp. 294-299 ◽  
Author(s):  
Lalitkumar Jugulkar ◽  
Shankar Singh ◽  
Suresh Sawant
Keyword(s):  
Experimental Validation ◽  
Shock Absorber ◽  
Numerical Data ◽  
Damping Force ◽  
Response Curves ◽  
Flow Area ◽  
Maximum Acceleration ◽  
Content Type ◽  
Shock Absorbers ◽  
Frequency Ratios

Purpose The work presented in this paper is concerned with mathematical modeling and experimental validation of mono-tube shock absorber. This paper aims to create damper model to predict accurately damping force, and experimental analysis is done by varying the various parameters, such as flow area in bleed(Ab), mass (M) and operating frequency(?). Design/methodology/approach Here, input is given in the form of sinusoidal excitation, and the output is received as a numerical data of the displacement transmissibility. These data are then processed to get the values of transmissibility and magnification factor for various frequency ratios. They are then plotted to have transmissibility and frequency response curves, as it is a generally accepted measure of how well the system is isolated from its surroundings. Findings It is better to have low transmissibility (larger bleed area), for lower suspension velocity, as it will reduce maximum acceleration transmitted to the sprung mass. However, for higher suspension velocity, bleed area should be low (higher transmissibility) to reduce displacement of tyre from road. Originality/value The development of faster vehicles and also the requirements of smoother and more comfortable rides have led to the fitment of dampers on almost on all present day vehicles. Shock absorbers have a significant influence on handling performance and riding comfort. Shock absorber plays an important role not only for comfort of the riders of the vehicle but also in the performance and life of the vehicle. However, no further reduction of vehicle vibration can be expected for using the optimum values of damping coefficient and spring stiffness for the shock absorber. Thus, it is necessary to make modification to improve the functions of shock absorber.

Modeling an Active Vehicle Suspension System With Application of Digital Displacement Pump Motor

2008 ◽  
Author(s):  
Xubin Song
Keyword(s):  
Control Strategy ◽  
Shock Absorber ◽  
Active Suspension ◽  
Suspension System ◽  
Vehicle Suspension ◽  
Damping Force ◽  
Independent Components ◽  
Displacement Pump ◽  
Vehicle Suspension System ◽  
Active Vehicle Suspension System

Vehicle suspension design can be simplified by using compressible fluid (CF) based struts. One single CF strut can provide both spring and damping force instead of two independent components of spring and shock absorber in a traditional vehicle suspension system. With the application of a digital displacement pump motor (DDPM) to modulate the fluid amount in CF struts, a hydraulic based active suspension can be developed. Each vehicle suspension corner (i.e., CF strut) can be linked to (at least) one cylinder of a multiple cylinder DDPM. Each cylinder has two poppet valves to allow exchanging flow between strut and accumulator. Those valves are actively controlled according to a properly designed control strategy. Thus DDPM can regulate the fluid flow to/from the CF struts to create a desired strut force at each suspension corner. This paper focuses on elaborating this novel active suspension using CFS and DDPM, and then presents a model that can well capture the macro-behavior of this new active suspension.

Modeling, Experiments, and Parameter Sensitivity Analysis of Hydraulic Electromagnetic Shock Absorber

2016 ◽  
Author(s):  
Sijing Guo ◽  
Lin Xu ◽  
Yilun Liu ◽  
Mingyi Liu ◽  
Xuexun Guo ◽  
...  
Keyword(s):  
Shock Absorber ◽  
High Reliability ◽  
Average Power ◽  
Hydraulic Motor ◽  
Damping Force ◽  
Shock Absorbers ◽  
Damping Characteristics ◽  
Thermal Fatigue Life ◽  
Electromagnetic Shock ◽  
Electromagnetic Shock Absorber

To improve the vehicle fuel economy and prolong the thermal fatigue life of the traditional shock absorbers, energy regenerative electromagnetic shock absorbers have attracted wide attentions. This paper discusses a hydraulic electromagnetic shock absorber (HESA), which has high reliability. A dynamic model of HESA is created in this paper, which shows that the damping force of HESA is composed of the electric damping force, friction damping force, the inerter force and the accumulator force. Influences of hydraulic motor and pipe diameter on the force are analyzed based on the modeling. The parameters of the nonlinear component accumulator are also studied experimentally. Both modeling and lab tests show that the accumulator force can counteract part of the effect of the inerter force, which is greatly beneficial for the vehicles. The damping characteristics and energy harvesting characteristics are also studied based on the lab tests. Results show that the damping coefficient of HESA ranges from 12000Ns/m to 92000Ns/m at a vibration input of 3Hz frequency and 5mm amplitude, and HESA has a unique damping characteristic which needs to be further studied for vehicle dynamics. In addition, the efficiency of HESA can achieve 30% at a vibration input of 3Hz frequency and 7mm amplitude with external resistance of 4 ohms. The average power at this excitation can reach 102 watts.

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