Study of Failure Analysis of a Fracture Crankshaft Pulley Used on a Truck Engine

Abstract

A pulley is a mechanism consisting of a wheel, with a groove between its two edges, which is fastened to a shaft. The belt usually passes along the groove of the pulley to give it the power of movement and rotation. In December 2016 there was a case of failure of the crankshaft pulley in a truck. This study aims to investigate the causes of fracture. Therefore, it was necessary to perform a failure analysis. Investigation methods included visual examination, scanning electron microscope analysis, chemical analysis of the material and mechanical tests. A finite element analysis (FEA) was also performed to quantify the stress intensity factor (KI) distribution in the crankshaft pulley that is near the crack tip. From the finite element analysis, it was found that K1 was greater than the fracture toughness (KIC) of the material. Therefore, the propagation of crack occurs from the initial crack until final failure.