The structural goal of all vehicles including buses is to increase structural stiffness while reducing the weight as much as possible by improving structural integrity or using the components efficiently.
In this study, the FE BUS model has been analyzed for the maximum stiffness of full structure while maintaining the weight to the same level of the specific bus considered. The analysis model consists of beam elements to represent major structural members of body structure and side rail of under-frame, and thin shell elements representing outriggers of under-frame and skin plate of body structure.
Torsional and bending stiffnesses have been increased simultaneously through redesigning the section property of major components using beam elements. Optimization module of a commercial code has been employed for the analysis.
Although the optimization process for increasing stiffness is not perfect, this study shows the improvement in the torsional stiffness by 15Z, and the bending stiffness by 21% while maintaining the weight at existing level.