Optimization Design Of Motorcycle Multi-Link Rear Suspension Based On Virtual Prototyping

As an important part of the motorcycle,the rear suspension system absorbs the vibration and impact of the road surface during the running of the motorcycle.As an important structural form,the hard point position of the multi-link rear suspension directly affects the ride comfort of the motorcycle,and the structural strength affects the safety of the motorcycle during driving.Therefore,it is of great practical value to optimize the design of multi-link rear suspension from the aspect of dynamics.In this thesis,a domestic motorcycle is taken as the research object.Aiming at the pitch vibration and vertical vibration of the motorcycle during driving,a motorcycle model is established.The ride comfort of the motorcycle is improved by optimizing the key hard points of the multi-link rear suspension.Based on the optimization results of the rear suspension hard points,the structural design of the key components of the rear suspension is completed,and the rationality of the structure is verified by transient strength analysis.Finally,the feasibility of the structural optimization scheme is verified by a real motorcycle test.The main research contents are as follows :(1)According to the three-dimensional digital model of the research object and the test data of the parts,the multi-body dynamics model of the whole motorcycle is established in VI-Motorcycle,and the ride comfort simulation analysis of the motorcycle is completed under the C-class road surface and the pulse road surface.The accuracy of the dynamic model is verified by comparing the simulation results with the test results.(2)Aiming at the pitch vibration and vertical vibration of the motorcycle,a multiobjective optimization mathematical model is established.Taking the key hard point position of the multi-link rear suspension as the design variable,the multi-objective optimization of the rear suspension hard point is completed by the NSGA-II algorithm.The optimization results show that the pitch vibration and vertical vibration of the optimized motorcycle are significantly improved under the C-class road surface and the pulse road surface.(3)Based on the optimization results of the hard point of the rear suspension,the structural design of the key parts of the rear suspension is carried out.The multi-body dynamics and finite element method are used to analyze the transient strength of the key parts of the rear suspension in combination with the actual working conditions,and the stress changes of the key parts of the rear suspension are obtained.The structure of the area with large stress is improved,and the rationality of the design is verified by experiments.(4)Through the comparative analysis of the real motorcycle test data before and after optimization,the results show that when the motorcycle is driving on the C-class road,the root mean square value of the body mass center pitch angle acceleration and the root mean square value of the vertical weighted acceleration is reduced by 15.0% and27.0% respectively;when the motorcycle is running on the pulse road,the peak value of the pitch angle acceleration of the body mass center is reduced by 43.5%,and the peak value of the vertical acceleration is reduced by 39.7%.The feasibility of the optimized design scheme is proved.