中文摘要：

对于面内阶跃载荷作用下矩形薄板的塑性动力屈曲问题,将临界应力和屈曲惯性项指数参数作为双特征参数求解.由相邻平衡准则导出失稳控制方程,由动力屈曲发生瞬间的能量转换和守恒准则,导出波阵面上的屈曲变形补充约束条件.失稳控制方程、边界条件、塑性波阵面上的连续条件和补充约束条件构成了定量求解两个特征参数和动力屈曲模态的完备条件.研究了矩形薄板塑性动力屈曲过程中板的厚宽比、冲击载荷大小、屈曲模态以及切线模量和临界屈曲长度之间的关系.

英文摘要：

The critical stress and the exponential parameter of the buckling inertia term are treated as the two characteristic parameters for the plastic dynamic buckling of rectangular thin plates subject to inplane step load.The governing equations are derived by the adjacent-equilibrium criterion and the supplementary restraint condition of buckling deformation at the fronts of compression waves is obtained in terms of the criterion of transformation and conservation of energy in the transient process of dynamic buckling.The stability equations,boundary conditions,continuity conditions at the front of plastic wave,and the supplementary restraint condition,which consist of the necessary and sufficient conditions of determining quantitatively the two characteristic parameters and buckling modes,are given.Based on these,in the dynamic buckling process of the rectangular thin plate,the relations between the thickness-width rate,the amplitude of impulsive loads,buckling modes,tangent modulus and critical buckling length are studied.