FEM Analysis Of GS125 Motorcycle Frame Strength

The strength of motorcycle frame is one of basic request in motorcycle design.Breaking of frame is a fearful strength failure.Breaking of the GS125 motorcycle happened several times in market.So we should analyse and improve it. We use PRO/E software to construct GS125 frame's 3D model,then induct the 3D model into ANSYS to creat the surface model through the PRO/E & ANSYS's interface program.At last we establish frame's FEM model by using shell element and mass element. Considering the dynamic effect while running , we apply maximum load to the frame FEM model, analyse its static strength. Calculated result show that the maximum stress area is located in the joint of frame upper tube & frame side tube and rear suspension plate,also its safety factor is lacking.The two area are also welding area, it often cause defect of welding because of welding worker's bad operation.It cause breaking in two areas.In this paper according to the simpleness and economy principle,we improve the frame structure by solely increasing the thickness of frame upper tube or frame side tube or rear suspension plate and increasing the thickness of the three parts together. Then we analyse four kind of diffirent improvement method.The result show that while solely increasing the thickness of frame upper tube or frame side tube or rear suspension plate,it only improve performance in single area,but while increasing the thickness of the three parts together,the performance in both areas are obviously improved.This indicate the direction of frame structure improvement.