Cross-sectional shape optimisation for thin-walled beam crashworthiness with stamping constraints using genetic algorithm

The energy absorption capacity of thin-walled beams (TWB) is important to reduce the occupant injury in the collision of automobile structure. At the conceptual design stage, engineers mainly depend on their intuition and experience when determining the cross-sectional shape of TWB. This paper presents the crashworthiness design and optimisation for the TWB with complex cross-sectional shapes under axial impact load using a genetic algorithm. The optimisation model is formulated to determine the optimal cross-sectional shape of TWB, which is to minimise the mass of TWB constrained with energy absorption and maximum peak force. Moreover, four stamping constraints, including minimal segment, draft angle, chamfer radius and assembly, are together considered to promote the complex cross-sectional shape in practice. A numerical example verifies the effectiveness of the optimisation model and shows powerful ability to obtain the optimal cross-sectional shape of TWB.