Optimal design of rear chassis components for lightweight automobile using design of experiment

With growing public concerns on the rising price of fossil fuel and the greenhouse gas emissions, the automotive industry is once again faced with the increased demand to develop more fuel-efficient vehicles. Savings in weight using lightweight materials such as aluminum can lead to increased fuel economy and reduction in pollution. Aluminum material has a weak point compared to the steel material in strength for life cycle. In this study, to design a lighter and more reliable chassis component using aluminum material as compared with existing steel chassis components, a new link shape was suggested by adding vertical ribs to an existing I-beam type link and to investigate how each design parameter makes an effect on the reliability and component weight. The design of experiment (DOE) was performed with six design parameters and two levels. Through the analysis of variance, three parameters which were the most influential on weight were selected. And then the response surface analysis was performed with two levels to find out the optimal dimensions. The weight of the aluminum link was 64% that of the steel link. The stiffness of the optimized aluminum link under all loads was more than 100% that of the steel link. The maximum von Mises stresses of the optimized aluminum link under all loads was equal or less than 20% of the ultimate tensile strength (58 MPa).