Study On Dynamic Characteristics Of Dual-tube Hy-draulic Shock Absorber By Multi-physics Coupling

According to the survey, the Hydraulic Shock Absorber is the most widely used component of the vehicle suspension system. The vehicle performance is closely with the dynamic characteristics of it. There are more and more manufactures put their attention to the performance prediction by CAE analysis, with the accelerated pace of vehicle product updates. Dynamic characteristics predictive analyses are related to the problem of fluid-structure interaction and thermal-mechanical coupling, or include all of them.The dual-tube hydraulic shock absorber was taken as the study object in this thesis. Tools of CAE (Such as CFD、FSI and TMC) are used to complete the study on dynamic characteristics and its influencing factors analysis. The research contents were included as follows:1. The basic research method of the dynamic characteristics was summarized. According to the research results by the domestic and foreign scholars, the research methods of the dynamic characteristics have been summarized, including the model type’s, trends, the advantages and disadvantages.2. The variation characteristics of dynamic characteristic parameter has been found by testing. First, starting from the structural characteristics and working principle of the object, Combined with the classical theory of fluid dynamics, structural mechanics, etc., the calculation formula of the damping force has been established. Through the test data we got the variation characteristics of inner friction, external characteristics, with the changing of the working conditions and the environment temperature.3. Combined the fluid dynamics theory and CFD technology, the internal flow field distribution characteristics and rebound damping force have been calculated under the low-speed conditions. With the CAE technology, obtained the variation of the rebound damping force in low-speed conditions according to the change of the structural parameters.4. Based on the fluid-structure interaction system dynamics, the variation of the rebound damping force and the influencing factors have been found through the analysis model built by ADINA FSI module.5. Established the TMC and FSI model of the dual-tube hydraulic shock absorber, the mechanism of heat and the dynamic distribution of temperature field are studied.Innovations involved in the subject as follows:1. Being different from the previous research that the CFD distributed parameter model have been established to study on the affection of the pre-gap for the Calculation accuracy. The results show that Gap needs to be controlled in20micron.2. Based on the fluid-structure interaction, the three-dimensional TMC model has been established. The mechanism of heat and the dynamic distribution of temperature field have been found. It is better to reveal the dynamic distribution law of the temperature field than the lumped parameter and Distributed parameter model built by previous.