Analysis of a vehicle wheel shaft failure

This paper describes an investigation which was carried out on a failed wheel/drive shaft component used on an unmanned, remotely operated vehicle for manoeuvring military targets. As many vehicles had been manufactured and delivered to customers it was necessary to establish whether it was thought likely that more failures might occur. A study of the broken shaft shows how vulnerable such a rotating component can be to failure by fatigue, even when operating under steady conditions, if basic preventative design actions are not taken. The analysis considers the effects of both transmission torque and weight (thus bending) upon stress levels and assesses their individual affect on the breakage and upon any subsequent modifications needed to improve the design. The drive shaft arrangement is compared with the feasible alternative of using a driven wheel arrangement rotating on a stationary axle. Findings confirm the importance of recognizing in advance the salient factors leading to fatigue and the necessity in paying adequate attention to detail during design and manufacture if long service life is to be achieved. (C) 1998 Elsevier Science Ltd. All rights reserved.