Strength and Stiffness Analysis of Modified chassis designs: A Case Study on Bishoftu Bus in Ethiopia

Abstract

Chassis is the “backbone” of every vehicle. It is the main component of vehicle in keeping the structural integrity. Ethiopia currently is far behind in vehicle manufacturing, with the capability of only assembling parts imported from foreign nations. The study focuses on the ZK6118HGA model bus, currently assembled in Ethiopia using a chassis imported from China. The research employs Finite Element Analysis (FEA) to evaluate the structural performance of the existing chassis design and explore modifications that accommodate the carbon steel and manufacturing capabilities of Ethiopia. The analysis considers four modified chassis designs that involve cross-sectional variations and addition of stiffeners. The results reveal that the use of RHS cross members, particularly in conjunction with stiffeners, significantly improves stress distribution and deformation control. The 4th case emerges as the most promising, demonstrating reduced stress of 158.12Mpa acceptable deformation of 5.1863mm, 11.48% weight decrease and comparable torsional and bending stiffness to the original design. The 4th case cross members are all RHS which are able to be produced here in Ethiopia. And the material used for this chassis is carbon steel produced in Ethiopia so the study concludes that the 4th case has a potential to facilitate local chassis production.