Dynamic Analysis and Optimization of a Chassis Mounted Bracket of a Truck

Abstract

The advancement of Computer Aided Engineering (CAE) makes industry to perform dynamic/static analysis of vehicle components in actual working environment. In the present work, a chassis mounted bracket of Eicher truck has been considered for dynamic analysis using the actual road vibration excitation. The bracket is used as a foundation to support the heavy spare tyre and mounted on the chassis. The dynamic forces subjected on the bracket can generate high stresses in the bracket, which also influences by the speed and different road conditions. High stresses may lead to structure failure or fatigue failure of the bracket. Generally, the components are overdesign to avoid such failures due to dynamic loading, which in turn increases the overall weight of the component/vehicle and affect the performance of the vehicle. In this study, a methodology is developed to dynamically analyse the mounting bracket using real time vibration excitation induced on the support structure of bracket. The end effect of the excitation on the bracket is further used to optimized the bracket. The mounting bracket has been designed and analysed using commercial packages as CREO and ANSYS Workbench respectively. Real time vibration signal is acquired in the form of acceleration on the base of bracket and used as an input dynamic force to the support of the bracket to perform transient dynamic analysis. The resultant stresses due to static structural and dynamic analysis are compared with yield strength of material to check the design feasibility. From the different analysis, it is noted that the chassis mounted bracket is overdesigned and, hence, optimization of bracket is performed to reduce its mass, while keeping the strength unaltered. Other FEA analysis is also performed on bracket like static structural analysis to check the total deformation in bracket due to dead weight of tyre and modal analysis to find the natural frequency of bracket. Using current methodology, a 12.25 % reduction in the bracket has been achieved.