Structural Response of Elliptical Cross-sectional Projectile under Bilateral Loadings

The structural response of an elliptical cross-sectional projectile obliquely penetrating into concrete target at high-speed is analyzed. The concept of the neutral axis is introduced based on the bending theory of arbitrary-section beams, a yield response model of a free beam with elliptical cavity section under the action of axial force and bilateral bending moment is established. The reliability of the yield response model under the action of axial force and bilateral bending moment is verified through numerical simulations and experimental results. The results show that, compared with the circular cross-sectional projectile with the same cross-sectional area, the bending resistance of the elliptic cross-sectional projectile is weakened on the short axis and strengthened on the long axis. The introduction of the initial roll angle of the elliptical cross-sectional projectile leads to a change in the neutral axis of its weak surface. When the neutral axis is near the long axis, the bending resistance of the projectile decreases. If the projectile enters the plastic yield state, the position of the plastic zone also appears in different directions of the projectile with the change in the azimuth of the neutral axis. The research results can be used to preliminarily judge the structural stability of the elliptical cross-sectional projectile at the initial stage of hitting a target, and provide guidance for the structural design of such a projectile.