刚塑性自由梁中部在横向冲击下的初始变形模式

研究了均匀矩形截面刚塑性自由梁中部在小尺寸、平头、圆柱形刚性弹体撞击下的三种变形模式,即梁的刚体平动、单铰变形模式和三铰变形模式。考虑了刚性子弹冲击后在梁上形成的剪切冲塞,分析了子弹通过冲塞作用在梁中部的剪切力可能引起的梁的弯曲变形,找出了梁的初始变形模式对子弹大小、梁的尺寸和材料性能的依赖关系。

Initial Deformation Modes of Rigid-plastic Free-free Beams under Transversal Impact

An analysis is presented in this paper for predicting the initial deformation modes of a rigid plastic free free beam with uniform rectangular cross section impacted normally by a small size of flat nosed solid cylindrical missile at the middle of its span.These deformation modes of the beam include translation as a rigid body,single hinge and three hinge modes.At a speed close to or above the ballistic limit,the missile generates a plug at the middle of the beam,at the periphery around the plug the transversal shearing strain is predominant.In this analysis,bending deformation of the beam caused by the shearing force of the missile acting on the beam through the plug is considered.The dependence of the initial deformation modes of the beam on the diameter of the missile,the size and the material property of the beam is obtained.