Within the context of vehicle suspension component characterization, that of shock absorbers is one of the more difficult to achieve, yet it is a very critical factor in the prediction of vehicle dynamic behaviour. Strongly non-linear output force functions are always linked to a frequency-dependent behaviour. Using the internal fluid-dynamic phenomenon with respect to a motorcycle shock absorber, different physical models of increasing complexity are presented: using these models it is possible to evaluate the importance of different factors, for example oil compressibility or oil inertia. Comparisons with experimental data confirm the validity of these models
In this paper, a non-parametric model is presented for representing compressible fluid struts (CFS) that are based on silicon fluid. The strut can be properly designed to replace the traditional spring and shock absorber for vehicle suspension application. For this study, the strut does not include damping function so that the analysis focuses on modeling the fluid compressibility of the spring function. The approach is to derive a series of mathematics equations in correspondence to the extracted data sets from the strut testing data. The pressure data can be characterized as dependent on precharge pressure, vibration applied on the strut, and friction existing between sealing and the strut rod surface. Every characteristic is represented by a (group of) simple equation, which is optimized based on characterized data sets, respectively. Finally the model is programmed in SIMULINK and validated by the collected testing data.
Based on the analysis of a new type of air spring and the nonlinear finite element theory, this paper, taking the mechanical properties of the new type air spring into consideration, put forward an assessment method: the Mooney-Rivlin model with higher order term simulates rubber layer, the rebar model represents the cord thread layer, the stiffness of the listrium and the controllable damping shock absorber is rigid body, the gas flow and the pneumatophore are in coupling. In addition, the method has been tested and verified by applying to a new type vehicle air spring. This paper offers a new assessment method for the development of air springs in vehicle suspension.
It has been a key problem that the analytical computation of a throttle slice deformation, for the design of shock absorber valves parameters. In this paper, the mechanics model of throttle slice under a spring pre-tightening was simplified into that under a micro-circle pressure. Using boundary and continuity constraints, the general equation for throttle-slice deformation under a micro-circle pressure was given, and by mathematical transformation, an analytical formula was established. With the practical example, the deformation of throttle slices on spring pre-tightening force at any radius was computed, and was testified by ANSYS. It is known that the results computed are close to that simulated, and the deviation is only 6.6 mm. It is shows that the method of deformation analysis of a throttle slice under micro-circle pressure is reliable, which has important reference value for throttle valves parameters design and characteristic simulation of shock absorbers.
Regenerative shock absorber is designed to convert the vibration energy losses from the vehicle suspension into electricity. This paper presents an experimental study on the dynamic characteristics of hydro-magneto-electric-regenerative shock absorber (HMERSA). Study was carried out by developing a prototype of HMERSA and testing its dynamic characteristics. The results were analyzed and discussed. Prototype of the HMERSA consists of hydraulic system and electric generator. The HMERSA was tested using a quarter car suspension test rig with input displacement in various frequency (1.3Hz, 1.5Hz, 1.7Hz) and for HMERSA’s various oil viscousity (ISO VG 10, 32, 46). Sprung mass acceleration and the generated electric power representing the dynamic characteristics of HMERSA were measured. Maximum power 2.5 watt and root mean square acceleration 0.172 m/s2 gained for HMERSA with oil viscousity ISO VG 10 at all excitation frequency.
Preview control of vehicle suspension system featuring MR shock absorber