Component sensitivity analysis of conceptual vehicle body for lightweight design under static and dynamic stiffness demands

At conceptual design stage, engineers mostly rely on their experience, intuition, and data accumulation when making decisions on conceptual vehicle body (CVB). This paper presents a component sensitivity method for the lightweight design of the CVB. Firstly, CVB is simplified as a frame structure consisting of box beams. Secondly, torsional stiffness, bending stiffness and frequencies are adopted to evaluate the global stiffness performances of the CVB frame. Thirdly, component sensitivity formulas are derived. Fourthly, two application examples of car and bus frame verify that the proposed method is efficient to guide the cross-sectional sizes modification. The sufficient condition to obtain positive frequency sensitivity is also discussed. And finally Vehicle Body-FDO software is released for free to implement this method.