Parametric study and protective performance optimization of a bolted vehicle body under blast impact

Traditional armored vehicles predominantly employ welded body structures, resulting in numerous welded joints that create structural weak points. Additionally, their rigid structural layout lacks flexibility to adapt to complex battlefield conditions. Replacing welded joints with bolted connections not only reduces structural vulnerabilities and eliminates welding-induced stresses but also enables rapid replacement of structural components based on operational requirements. Consequently, a body design concept utilizing bolted connections instead of welding has been proposed. This study employs a multi-material element and fluid-structure interaction algorithm to simulate the dynamic response of a light armored vehicle under explosive impact. Simulation results are compared with experimental data to validate model accuracy. By modifying the original vehicle connection method, a bolted body model was obtained. Whole-vehicle explosion simulation was used to analyze the bolted body, showing that the forces on the dummy’s left and right lower tibia were reduced by 10.6% and 9.8%, respectively. The effects of bolt preload, assembly clearance, and strength grade on the protective performance of the bolted body were investigated. A multi-objective optimization was performed on the bolted body to obtain an optimal design solution for this optimization problem. The design was validated through full-vehicle explosion simulation. Results showed that the forces on the dummy’s left and right lower tibia decreased by 13.2% and 23.2%, respectively, compared to the pre-optimization state. This solution effectively reduces the impact on the body and enhances its protective capability.