Analysis of Material Failure Due to Rigidity Changes on a Motorcycle Frame Body Structure

Abstract

One of the most important things on a motorcycle is the frame. The motorcycle frame is a structure that supports almost all of motorcycle components, such as the engine, front and rear suspension, fuel tank, and others components. The purpose of this research is to determine the cause of the failure of the motorcycle frame in based on actual conditions in the field. In this study, a case study was carried out on a sport-type motorcycle frame with 150cc engine capacity, using a trellis-type frame, and had traveled 10,000 km as indicated on the odometer. The results of the case study and analysis on the failed part, it was found that the main cause of the failure of the motorcycle frame or frame body was due to the bolt flange on the engine hanger having a torque below the standard. This happens due to consumers who make modifications and add accessories. So the torque below the standard or low torque causes the frame body to break as a result of the reduced rigidity of the frame body structure and also as a result of repeated dynamic loads on the welding area, which is included in the HAZ area, which is the weakest part of the welding joint. Failure or fracture can occur as a result of the continuous load received on the frame structure, resulting in fatigue failure. The failure also occurred at the low torque bolt flange earlier.