Research on transient response of pistol bullet impact on bulletproof helmet based on multiscale method

In order to accurately simulate the transient mechanical response of a bulletproof helmet when impacted by a bullet, this study employed a numerical simulation of bullet infiltration while wearing a bulletproof helmet based on composite multiscale analysis. The stress-strain curves of the UHMWPE fiber bundles were obtained through tests, and the material properties of the macroscopically homogenised UHMWPE unidirectional fiber layer were derived based on the progressive multiscale analysis of composite materials. A 3D-Hashin progressive damage ontology model was developed for simulating the mechanical properties of UHMWPE ballistic helmets. Numerical simulations of pistol bullet infiltration into UHMWPE ballistic helmets were conducted, and the numerical model was validated through 3D-DIC tests. The results demonstrate that the material parameters of the macroscopically homogenised UHMWPE unidirectional fiber layer, obtained through multiscale analysis, can accurately simulate the deformation and damage process of the ballistic helmet during penetration by a pistol bullet. The damage modes include fiber tensile damage, matrix tensile damage, matrix compression damage, and a wide range of delamination damage. Additionally, the mechanical properties of the UHMWPE interlayer have a significant influence on the formation of the bulging bag in the impact process.