FAILURE ANALYSIS IN A CRANKSHAFT PULLEY TRUCK HEAVY DUTY
Husaini* , Sharwin Novriandika, Muhammad Rizal, Teuku Edisah Putra
Computational Mechanics Laboratory, Department of Mechanical Engineering,
Universitas Syiah Kuala
Jl. Tgk. Syech Abdurrauf No. 7, Darussalam, Banda Aceh 23111. Indonesia
*E-mail: husainiftm[at]unsyiah.ac.id
Abstract
Pulley is a mechanism consisting of a wheel that is fastened to a shaft that has a groove between the two edges around it. In its use pulleys always pair with a belt. The belt is usually used on the groove of the pulley to move power and rotation. Pulley failure often occurs due to excessive load and rotation. The case in this study was the failure of the crankshaft Pulley from a Truck that occurred in December 2016 so that the heavy duty truck could not operate anymore. The truck has only been used for around 20 months. The purpose of this study is to find the cause of failure. Therefore, it is necessary to perform a failure analysis where in this case an experimental study was conducted. The analysis was carried out starting from inspection and visual observation. And then also carried out laboratory tests namely hardness testing and observations on the surface of the crack using Scanning Electron Microscope (SEM). From a series of analyzes, the results show that the initial cracks occur in the corners around the key way. Because the pulleys experience a dynamic load, the initial cracks propagate to a final broken failure. Another result was obtained that the hardness of the outer part of the pulley around the key way, where the thickness of the hardness reaching 4 mm almost reached the thickness of the pulley around the keyway which was about 5mm.
Keywords: Crankshaft pulley; Crack propagation; Truck; Hardness; Failure analysis
Topic: Mechanical Engineering