Abstract: Light weight design is introduced in the early phase of a new car body in white(BIW) development. SFE-Concept implicit parametric BIW model is build. The shape, size, position and gauge of BIW parts are balanced and all performance satisfy design target through multidisciplinary optimization. So this process reduces BIW mass maximally. BIW is divided into different optimization regions according to its performance characteristic for controlling the number of design parameters and the design of experiment(DOE) samples. Approximation model is created through DOE. Analysis and optimization time are controlled through optimizing approximation model. Finally an BIW meeting multidisciplinary performance target is obtained, saves 12 kg and lightweight effect is 4.5%. The design parameters percent contribution and main effect plots are obtained through analysis of variance (ANOVA). The rules between design parameters and performances (mass, stiffness, vibration modes and passive safety) are evidence according to percent contribution and main effect plots.

Key words: Multidisciplinary optimization, Analysis of variance (ANOVA), Body in white, Light weight