Numerical and theoretical modeling of the elastic-plastic bulging deformation of UHMWPE composite laminate under high-speed impact

Abstract

The bulging test is crucial for evaluating the ballistic resistance of ultra-high molecular weight polyethylene laminate. However, the underlying deformation mechanism and the quantitative description of the bulging deformation, including the apex displacement and the location of the boundary of the deformation region (traveling hinge), are still lacking due to the complex dynamic elastic-plastic response under impact. In this paper, the bulging deformation of UHMWPE laminates is computationally and theoretically studied. First, an orthotropic elastic-plastic damage model considering the strain rate effect is established, which can describe the dynamic response of UHMWPE laminates in agreement with the experimental results. Secondly, the results show that the apex displacement increases linearly with the increase of impact velocity but decreases nonlinearly with the thickness. In contrast, the traveling hinge moves outward at a constant speed, independent of the thickness and impact velocity. It can be explained that the membrane stretching dominates the bulging deformation. Based on these results, an analytical model is proposed to quantitatively predict the bulging deformation, which can be used to predict the effects of the mass and the impact velocity and thickness on the bulging deformation. The work is meaningful for the design of UHMWPE laminates with high-impact resistance.