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This paper documents the design and verification process of a modular spaceframe platform for SUV, hatchback, sedan and station wagon conducted at the Institute for Advanced Vehicle Systems (IAVS) of the University of Michigan-Dearborn. The goal of the project was to show the feasibility of a cost effective family of vehicles for low volume markets and reduce the body structure mass while meeting current industry and federal standards. For low volume markets the cost of using spaceframe construction is more economical compared to the traditional unibody construction. Cost is further reduced because a family of low volume vehicles would share a lot of common parts. Also, spaceframes can use extruded sections joint by cast nodes, which are both inexpensive. The results discussed in this paper show the CAE work done on beam models for a family of vehicles including, sedan, station wagon, hatchback and SUV.

The automotive industry is continuously investigating means for producing lighter-weight vehicles in order to improve fuel efficiency and reduce emissions. Lightweight materials, such as aluminum, are often used to replace steel in automotive body structures, such as hoods, decklids, fenders, and their corresponding reinforcements. To further reduce weight and improve stiffness, sheets of different gages and/or properties are welded together prior to stamping to form “tailored” blanks. The presence of the weld and the gage mismatch in these blanks, often result in premature failure, which can be expressed as a shift in the forming limit diagram. Several process variables affect this change in deformation behavior including the welding process used to join the blanks, the weld orientation, the weld geometry, and the mechanical properties of the weld and the base materials.

The use of tailor welded blanks (TWBs) in automotive applications is increasing due to the potential of weight and cost savings. These blanks are manufactured by joining two or more sheets of dissimilar gauge, properties, or both, to form a lighter blank of desired strength and stiffness. This allows an engineer to “tailor” the properties of the blank to meet the design requirements of a particular panel. TWBs are used in such places as door inner panels, lift gates, and floor pans. Earlier investigations of the use of TWBs targeted steel alloys, but the potential of further weight savings with aluminum TWBs is gaining interest in the automotive industry. Unlike steel TWBs, the welds in aluminum TWBs are not significantly stronger than the base material and are occasionally the fracture site. Additionally, the reduced formability of aluminum, as compared with drawing-quality steels, makes the application of aluminum TWBs more difficult than steel TWBs.