Design and Optimization of Variable Rectangular Cross Section Chassis for On-Road Heavy Vehicles

All the loads generated by other components of heavy vehicle are transferred to its chassis. Chassis related failures are few but the damages to the safety of occupant are huge; sometimes it leads to fatal accidents. In order to overcome this, the chassis has to be optimized based on static and dynamic loads by ensuring a uniform distribution of stress and strain. The shape and cross section of the chassis gives a resistance to the above mentioned loads. The cross section of the chassis structure of all on-road vehicles is uniform despite the variable loads. In this work, variable cross section chassis of an on-road heavy vehicle is designed by keeping optimum sections. Bending moment of the chassis has been mathematically related with section modulus of the chassis. Genetic algorithm based procedures have been used to optimize the height, width and thickness of the chassis cross section. Coding in C language is used to automate the genetic algorithm procedures. For benchmark study, 3D models of optimized and existing chassis of an on-road heavy vehicle were developed. Finite element analysis reveals that the optimized chassis has less failure possibilities due to lower stress values and uniform distribution when compared to those from the model of existing chassis.