Simultaneous Free-Size, Gauge, and Composite Optimization for Automotive Chassis Design

Rising gas prices and increasingly stringent vehicle emissions standards have pushed automakers to increase fuel economy. Mass reduction is the most practical method to increase fuel economy of a vehicle. New materials and CAE technology allow for lightweight automotive components to be designed and manufactured, which outperform traditional component designs. Topology optimization and other design optimization techniques are widely used by designers to create lightweight structural automotive parts. Other design optimization techniques include free-size, gauge, and size optimization. These optimization techniques are typically used in sequence or independently during the design process. Performing various types of design optimization simultaneously is only practical in certain cases, where different parts of the structure have different manufacturing constraints. This paper presents a case where this simultaneous optimization approach is used to redesign an automotive front crossmember using carbon fiber sheet moulding compound and carbon fiber non-crimp fabric. This method is successful in producing a design that is 50% lighter than its existing steel counterpart, while maintaining equal stiffness to the steel design.