抄録
A new method for crashworthiness optimization of vehicle structures is presented, where an early design exploration is done by the optimization of an "equivalent" mechanism approximating a vehicle structure. An equivalent mechanism is a network of imaginary beams joined by prismatic and revolute joints with special nonlinear springs. These springs are designed to mimic the force-displacement characteristics of thin-walled beams subject to axial crash and transversal bending. A number of finite element (FE) models of beams with typical cross sections and wall thicknesses are analyzed to build a surrogate model that maps a property of nonlinear spring to the corresponding FE model. Using the surrogate model, an equivalent mechanism is optimized for given design objectives by selecting the properties of the nonlinear springs among the values that can be realized by an FE model. After the optimization, the component FE models corresponding to the optimal spring properties are "assembled" into a FE model of an entire structure, which is further tuned to final design. A case study with a vehicle frontal frame demonstrates that the new approach can obtain a better design with less computational resources than our previous best result.
