Optimization of loading path for internal high-pressure forming of instrument panel tube beam based on NSGA-II

Abstract In the process of hydroforming of instrument panel tube beams (IPTB), the rationality of the internal pressure loading curve (IPLC), and the axial feed curve (AFC), directly determines the success or failure of the forming. However, due to their inherent limitations, traditional analytical methods, experimental methods, and numerical simulation (SIM) methods are difficult to achieve ideal results in the matching design of multivariable loading paths. To this end, this paper combines the elite retention non-inferior sorting genetic algorithm (NSGA-II) with commercial finite element software based on dynamic explicit algorithm and realizes the optimal design of the loading path by adjusting the values of key control points on the IPLC and the axial feed speed curve (AFSC). The optimization results show that by reasonably setting the population size (PS) and number of generations (NG), a loading path closer to the optimal can be obtained compared with the manual optimization method, and the wall thickness (WT) distribution of the IPTB is more uniform. In addition, this method can generate multiple Pareto optimal solutions simultaneously in one optimization, providing more options for the formulation of loading paths.