钢质圆柱壳在侧向局部冲击荷载下的变形及失效破坏

Dynamic response and perforation failure of cylindrical shell subjected to lateral local impulsive loading

基于动力有限元程序LS-DYNA及随动塑性Cowper-Symonds模型,对两端固支钢质薄壁圆柱壳经受半球头弹体侧向局部冲击的非线性动力响应问题进行数值模拟,获得了不同冲击条件下圆柱壳的变形及破坏模态,并研究了弹体在不同周向冲击倾角时壳壁产生穿透性破裂的最小速度(临界破裂速度)。研究表明,圆柱壳破坏模式与弹体冲击倾角θ0、冲击速度V等因素密切相关,将发生局部凹陷、碟形变形及穿透现象,且临界破裂速度随冲击倾角的增大而增大。研究结果可应用于圆柱壳在侧向局部冲击作用下的毁伤预测,从而为圆柱壳结构的安全防护设计提供理论依据。

By means of the explicit nonlinear dynamic finite element computer code LS-DYNA and the plastic kinematic Cowper-Symonds model, the nonlinear dynamic response process of fully clamped cylindrical shell subjected to lateral local impact by a hemispherical-nosed projectile was numerically simulated. The dynamic deformation and failure modes of cylindrical shells under different impact conditions were acquired. The minimum impact speed generating cracks through the thickness of the shell wall, termed as the speed for rupture, was studied. The results demonstrate that the failure modes of cylindrical shell relates to the circumferential impact oblique angle and impact speed. The local dent, dish-shaped deformation and perfoation may occur. The speed for rupture increases with the increase of angle of obliquity. The results can be applied to the engineering prediction of the damage or safety of cylindrical shell under lateral local impact and can provide theretical reference to safety design.