【摘要】 利用Ansys/LS-DYNA建立内部受半球头弹体横向冲击的弯管模型,采用Cowper-Symonds模型模拟材料关系,采用破裂应变失效准则定义失效破坏。分析弯管的穿透破坏模式,研究弯管外径D o、弯管厚径比t/D o、弯管曲径比R/D o、弹体直径与弯管直径比D m/D o、弹体长度与弯管直径比l m/D o与弯管临界破裂动能E r的关系。研究表明:半球头弹体冲击弯管存在两种穿透破坏模式——花瓣型破坏和拉伸型破坏。花瓣型破坏是管壁环向和径向应力主导的沿轴向和径向的同时撕裂;拉伸型破坏是弹体沿管壁滑移引起的管壁拉伸破坏。弯管D o对E r几乎无影响;E r随t/D o、R/D o、D m/D o和l m/D o增大而增大。更多还原

【Abstract】 A finite element model that the elbow was impacted by a hemispherical-nosed missile was set up by using Ansys /LS-DYNA software. The plastic kinematic Cowper-Symonds hypothesis was adopted and the rupture strain failure criterion was used to define the failure process. The failure mode of the elbow had been analyzed. The relationship of the critical rupture kinetic energy E r with elbow outer diameter D o,thickness-diameter ratio t/D o,curvature-diameter ratio R/D o,the diameter ratio of missile to elbow D m/ D o and missile length to elbow diameter ratio l m/ D o was investigated. Research indicates that there are two penetration failure modes of the elbow impacted by hemispherical-nosed missile,that is petalling and dishing. The petalling failure is the simultaneous avulsion dominated by the hoop stress and radial stress. The dishing failure is the tensile failure caused by the missile slipping along the elbow. The effect of D o on E r can be neglected. E r increases with the increase of t / D o,R/D o,D m/ D o and l m/ D o.更多还原