含初缺陷裂纹损伤梁的冲击动力屈曲

Dynamic buckling of cracked beams with initial geometric imperfections subject to axial impact

由Hamilton原理导出考虑初始缺陷及横向剪切变形时裂纹梁的动力屈曲控制方程;应用断裂力学中常用的线弹簧模型将裂纹引入到屈曲控制方程中;基于B-R动力屈曲判断准则,采用数值方法求解了受轴向冲击载荷作用时裂纹梁的动力屈曲;对比讨论了不同冲击速度、初始几何缺陷大小以及分布形式等因素对梁冲击动力屈曲的影响。

This paper investigates the dynamic buckling of a cracked beam with geometric imperfections subject to impacting. For a cracked beam, the dynamic buckling control equations are derived from Hamilton＇s principle using the first order shear deformation theory. The discrete equations are obtained using the finite difference method. The effect of crack is taken into account in buckling control equations using line-spring model of fracture mechanics. According to the B-R dynamic buckling criterion, the critical velocity of dynamic buckling of cracked beams is obtained. In addition, the effects of impact velocity and initial geometric imperfections on the impact dynamic buckling of perfect beams and cracked beams are discussed.