Structural analysis and optimization of a low-speed vehicle body

The low-speed vehicle (LSV) is being employed for various usages. The body of the LSV is usually made of the aluminium space frame (ASF) type rather than the monocoque or unitary construction type. The reason is that it is easier to reduce mass efficiently while the required stiffness and strength are maintained. A design flow for the LSV is proposed. Design specifications for structural performances of the LSV do not yet exist. Therefore, they are defined through a comparative study with general passenger automobiles. An optimization problem is formulated by the defined specifications. First, the A-pillar which has an important role in structural performance is selected, and the candidates of reinforcement in the pillar are determined from topology optimization to maximize the stiffness. Based on this, the thicknesses of the cross-sections are determined to minimize the mass of the body while design specifications are satisfied. The optimum solution is compared with an existing design. The optimization process has been performed using a commercial optimization software system, GENESIS 7.0.