Finite Element Analysis And Optimization Of Vibration Isolation Performance Based On AMESim Of Suspension Hydrobushing

As long as the consumers’ requirement to the automobile ride comfortableness is higherday by day, and the domestic and foreign related laws are increasingly stricter, how toimprove NVH performance of cars has become a hot research issue. As an importantvibration-isolating component of suspension system, the hydrobushing has better dynamiccharacteristics to reduce the vibration and noise compared with the traditional rubberbushing. So, it is widely used in senior cars. In China, the design ability and application ofhydrobushing are late start, therefore there are some difficulties in design theory andtechniques.Combined with the Science and Technology Program of Jilin Province"research onvibration comfort key technology of passenger car", the modeling method, the vibrationisolate performance match and optimization of hydrobushing are studied in this thesis. Themain contents are as follows.Firstly, in order to understand the word principle and establish the3D geometric modelof hydrobushing, the entity structure is cut. Based on the geometric model, the finiteelements mesh models are formed in HyperMesh and imported into FSI software ADINA tobuilt FSI finite element model of hydrobushing. The static and dynamic simulation of theFSI model are conducted. In order to validate the model, the dynamic characteristics rig testis taken and compared to the simulation result. According to the verified model, two keyparameters are computed: equivalent piston area of main rubber spring and volume stiffnessof single fluid chamber.The parameters will provide data for the parametric model asfollows.Then, on the basis of bond graph model and lumped parameter model, the AMESimsimulation model of hydrobushing is built in software AMESim. Based on the describingfunction method, the original simulation data from AMESim model is processed into the dynamic stiffness and loss angle curves in. The dynamic simulation curves agree withcorresponding test curves. The sensitivity analysis of modeling parameters to the dynamiccharacteristics of hydrobushing are presented via AMESim model. It will provide the basisfor the selection of design variables in the late optimization.Finally, according to performance-match analysis on simple vibration isolate systemand the road test of the domestic and imported cars, the matching principle betweenhydrobushing and suspension system is proposed, meantime the optimization object isdetermined. In accordance with the two optimization projects from the object, the authorutilizes the powerful simulation capabilities of AMESim and genetic algorithm tool inMatlab to optimize the performance of hydrobushing and compares the optimization resultsof the two projects. The structure of former hydrobushing is redesigned based on the finaloptimizing result.Generally speaking, different suspension systems have different demands to thevibration isolate performance of hydrobushing. The study in the dissertation can providetheoretical foundations and research methods in the design process of hydrobushing.