Research On Optimal Design Of Properties Of Twist Beam Suspension

With the development of automobile industry,vehicle has become one of the main means of transportation that people rely on most,and compact car with high economy and energysaving have become the first choice of many people.Most of these compact car have torsion beam rear suspension.Torsional beam used for supporting the impact,is an important part of the chassis system,its performance plays a crucial role in the vehicle ride comfort,smoothness and safety,especially its fatigue durability,has become one of the most concerned problems of enterprises and many car owners.It is of great practical significance to analyze and research the properties of torsion beam accuratelyThis paper takes the torsion beam of a domestic vehicle as the research object,and carries out the following research work:The parameters of the whole vehicle are obtained,the torsion beam is considered as a flexible body,the rigid-flexible coupling dynamics model of the vehicle is established,the influence of the nonlinear characteristics of the bushing on the model precision of the suspension system is analyzed,and the accuracy of the dynamics model has been improved.according to the inverse dynamics theory,Based on the multi-body model and the internal load spectrum of suspension system measured by road test,the external load spectrum of wheel center is obtained in Femfat.lab software,then,the load spectrum of key points of torsion beam is obtained through the multi-body dynamics simulation analysis.using the quasi-static method and the modal stress recovery method,analyze the fatigue performance of the Ontology structure by combining the EN curve of the material,and analyze the fatigue performance of the weld structure by combining the SN curve of the weld.finally,The results of the two methods are analyzed and researched,and the reasons of the similarities and differences between the two methods are summarized.Then the fatigue bench test was carried out to verify the fatigue performance of the torsion beam.The finite element model of torsion beam was established to analyze and verify its stiffness and strength performance.and a preliminary improvement of the torsion beam's structure is made based on the above performance calculation results.then,the structure optimization design of the torsion beam was carried out by Taking the slab thickness of the torsion beam as the design variable and combining with the agent model and the optimization algorithm.finally,The first order natural frequency of the torsion beam was increased by 11.5%,the fatigue performance was improved,and other performances still meet the design requirements after optimization.