Structural Optimization And Analysis Of An Electric Motorcycle Frame

The market competition of electric motorcycle industry is becoming increasingly fierce.Cost control and technological innovation become the necessary means for enterprises to survive and develop for a long time.The frame of electric motorcycle,as the force skeleton part of the whole vehicle,plays the role of connecting other parts of the body.It is subject to complex external loads.It not only needs sufficient strength,but also matches reasonable stiffness and dynamic performance.The research on lightweight optimization design of electric motorcycle frame can effectively reduce the production cost,shorten the product development cycle and reduce the development cost investment.At the same time,it is of great significance to promote the development of electric motorcycle industry.This paper chooses an electric motorcycle frame of an enterprise as the research object,mainly uses Ansys Workbench software for finite element analysis and structural optimization,and finally makes a prototype test and verification.The main work and conclusions of this paper are as follows:(1)The initial 3D model of the frame is established in CATIA software,and the structure of the frame is simplified.On the weld treatment,the solid weld is added in 3D.According to the basic theory of finite element,the simplified model is meshed by shell element and beam element in Ansys Workbench software,and the finite element analysis model of the frame is established.(2)The static strength finite element analysis model of the frame is established by using the design Simulation optimization module of Ansys Workbench software.The stress values of key points are calculated and tested by physical stress test.The accuracy of the finite element model is verified by comparison.On this basis,the anti-light impact performance analysis and stiffness analysis are carried out,and the shortcomings of higher stiffness are found.Finally,the first six natural frequencies of the frame are obtained by modal analysis.By calculating the maximum excitation frequencies of various pavements,the comparison shows that the natural frequencies of each order of the frame are far greater than the maximum excitation of the pavement,so it will not cause resonance.(3)Aiming at lightweight,the design Xplorer optimization module in Ansys Workbench software is used to optimize the size of the frame,which takes the quality of the frame as the objective function,takes the material strength condition as the constraint condition,and takes the wall thickness of the key components as the variable.After optimization,the quality of the frame changes from 13.2kg to 11.6kg,and decreases by 14%.After optimization,the strength of each part meets the design requirements,and there is no stress.Concentrated,but the torsional stiffness of the frame decreases to a certain extent,but it is still higher than the recommended value.Through comparative analysis,the local structural optimization is carried out in the middle of the frame,and the torsional stiffness of the frame is in a reasonable range.The strength and mode meet the requirements of the frame.Finally,the frame mass is 11.9kg,and the final lightweight effect is 12%.Finally,through the trial-manufacture of the prototype,stress measurement,light impact test,stiffness test and modal test are carried out,and the test results are compared with the theoretical analysis values to verify the reliability of the optimization scheme,the reliability of the finite element model and analysis method,which has guiding significance for the development of similar frame.