Lightweight Design Of Motorcycle Frame

With the continuous development of computer and structural optimization technology,lightweight design has become one of the main directions of mechanical design and manufacturing.As an important load-bearing component of motorcycles,the effective lightweight design of the frame is of great significance.In this study,considering the structural peculiarities of the frame pipe fittings,two frame models of different unit types are established,and then the frame models are analyzed for the strength,stiffness and modal performance of the frame models under multiple working conditions.At the same time,the two frame models are compared.The analysis result of the model.On this basis,a multidisciplinary optimization design method based on strength,stiffness and modal is proposed.First,based on the finite element pre-processing software Ansa,the midplane and midline of the frame pipes were extracted,and the shell element frame model and the beam element frame model were established,which laid the foundation for the performance analysis of the two different element types of frame models in the later period.Then,a more comprehensive performance analysis(modal analysis,stiffness analysis and strength analysis)of the two different unit types of frame models was carried out to verify the accuracy of the beam unit frame model.The main contents include: 1)Free modal and constrained modal analysis were carried out on the two frame models,and the first ten order modal frequencies were analyzed to evaluate the vibration characteristics of the frame;2)The rigidity analysis(the torsion conditions and the bending conditions analysis)of the two frame models was mainly carried out to evaluate the ability of the frame to resist deformation.3)The corresponding loads were extracted through enterprise standards and multi-body dynamics.And the six-condition strength analysis of the two models was carried out;4)The strength analysis was verified through the frame test and the whole vehicle road test.Finally,a total of 22 parameters of the diameter and thickness of the 11 sets of pipes of the frame were selected for experimental design,and the parameters with the most optimized space were selected as the design variables,and the constraint conditions were selected from the strength analysis,stiffness analysis and modal analysis.The minimum mass was the optimization goal,and the optimization design of the frame was carried out in the Isight software;the goal of reducing the total mass of the optimized frame pipe fittings by 7.7% has been achieved.The performance simulation analysis of the optimized frame model was carried out again to verify the accuracy of the scheme.