Abstract:Abstract: Ultra-high molecular weight polyethylene (UHMWPE) laminate, plane sandwich and spherical sandwich are researched by ballistic penetration experiments, and lower anti-penetraion performance of convex spherical structure is found than that of plane structure. Disadvantage of initial curvature of spherical structure is elementarily analyzed based on experimental phenomena. Ballistic penetration of UHMWPE laminates with different curvature is numerically simulated by DYTRAN FEM software, and curvature influence on ballistic properties is analyzed. Main cause of ballistic performance degradation is considered to be deformation restriction and the induced stress concentration due to initial curvature.