Stress Analysis and Design Improvement for Commercial Vehicle Frames With Bolted Joints

Abstract

Structural failures such as crack initiation often arise near the bolted parts of the side member and trunnion bracket of some commercial vehicles. To prevent these problems, a designer should be able to analyze with confidence the bolted joints of the structures, and this will require a reliable and practically simple bolted joint modelling technique. Once the modelling technique is established with experimental verification, the key design varibles must be identified in order to alleviate the level of the stress concentration near the problem region. The purpose of this paper consists of two major parts: the establishment of a simple and practical bolted joint modelling technique and the determination of the key design variables for design improvement. Utilizing the established joint modelling technique, a number of finite element calculations are carried out for the analysis of the system consisting of the vehicle side member and trunnion bracket. The numerical results have indicated that the torsional rigidity of the frame cross section and the trunnion bracket size are critical design variables.