Abstract:

To solve the problems of low efficiency and difficult convergence of multi-variable nonlinear dynamic structure optimization， this paper proposes a Subdomain Hybrid Cellular Automata for Thickness optimization algorithm （SHCA-T） and multi working condition SHCA-T algorithm to solve the thickness optimization of the body skeleton， so as to realize efficient optimization design of the crashworthiness of the body skeleton under multiple working conditions. The algorithm includes an outer loop and an inner loop： the outer loop is to realize minimization of target mass by conducting crash finite element analysis （FEA）， calculating output responses and updating target mass； the inner loop is to make the current mass of the inner loop to converge to the target mass by adjusting cell thicknesses according to internal energy densities of current cell and neighboring cells and PID control strategy， and finally make the cell internal energy density distribution as close as possible to the step target internal energy density function. In order to validate the accuracy and efficiency， the SHCA-T and multi working condition SHCA-T algorithms are used to solve the thickness optimization problem of body frame under side collision and side column collision. The optimized results obtained from the SHCA-T and multi working condition SHCA-T algorithms are compared with the results from parallel Pseudo expected improvement criterion for parallel EGO algorithm. The results show that the SHCA-T and multi working condition SHCA-T algorithms have higher global search efficiency under the condition of equal convergence accuracy.

Key words: hybrid cellular automata （HCA）, subdomain hybrid cellular automata for thickness optimization （SHCA-T）, body-in-white （BIW）, lightweight design, crashworthiness optimization