Abstract: In order to study the dynamic response of a projectile during penetration,a new way within the framework of finite element method,based on Lagrange eight-node constant stress hexahedral continuum elements in LS-DYNA,is explored to get the dynamic bending moment,axial force and shear force along the penetrator cross section.The typical distortion mode of a single plastic hinge failure mode coupling axial force with bending moment on oblique penetration are studied.It is a conservative condition for kinetic energy penetrator(KEP) design to analyse the inertia load on normal penetration,and to combine axial load and lateral load on linearity interaction surface.