The application of aluminum Body-In-White has several technical barriers in press forming, joining, and chemical conversion treatment processes. Among them, the optimization of joining processes with which structural stiffness and durability will be assured might have the key role for the success of aluminum applications to BIW.
In this study, stiffness strength and fatigue strength of BIW joints with aluminum sheets were evaluated as a function of joining methods, such as resistance spot welding and weld bonding, via both experimental and analytical routes(FEM). For the evaluation, single-lap joint and T-shaped joint were made, with each joining method, as variation of pitch, sheet thickness and even materials - steel sheets.
Based on the experimental and FEM analysis results, the optimum joining method for the aluminum BIW which is suitable for weight saving and has equivalent stiffness and strength to steel is suggested. In addition for obtaining optimum processes with improved stiffness and strength of the joining method, design parameter, such as the influence of the spot pitch on the structural joint stiffness and the minimum wall thickness of aluminum which is able to maintain the equivalent stiffness and strength to steel are discussed.