Study On Dynamic Response Optimization Design Of 250 Motorcycle Frame

With the improvement of people's living standard in our country,high-power motorcycle has gradually become the love of ordinary consumers.The vibration of motorcycle is mainly caused by the road and engine excitation to the frame in different driving conditions.At present,many small and medium-sized enterprises in China seldom optimize and improve the dynamic characteristics of vehicle frames through scientific and systematic experiments and simulation analysis.Therefore,it is particularly important to analyze and study the dynamic characteristics of motorcycle frame and improve the vibration of the whole vehicle.In this paper,a 250 motorcycle frame is taken as the research object.Firstly,the model is simplified and meshed,and the modal simulation analysis is carried out to obtain the inherent attribute parameters of the frame.Then,the experimental modal analysis of the frame is carried out.Secondly,the parameter results of the two analysis methods are compared to verify the accuracy of the frame finite element model.Finally based on the model of road spectrum data analysis,based on the need to optimize the sensitivity analysis approach,selecting the thickness of the section as design variables,the minimum and maximum size of thickness limit for geometric constraint conditions,the frame of the first-order natural frequency and selected point Z weight to the acceleration root mean square value decrease as the objective function of motorcycle frame is optimized.The optimization results show that the frame mass is reduced by 13%,the first-order natural frequency is improved,the resonance caused by engine and road excitation is avoided effectively,and the overall dynamic performance is improved.This paper analyzes dynamic characteristics of frame structure optimization,this not only reduces the enterprise of research and development as a result of blind design risk,and save the development money and shortens the development time,and left behind the precious frame finite element model for the enterprise and relevant technical methods and data,development of new type of frame has certain reference significance for the future.