通过引入曲面弯曲的等度量变换，给出了受冲击球壳的变形模态；接着，分别假定材料为弹性或刚塑性，基于能量守恒，得到了壳体和撞击体在运动过程中的控制方程；最后，对所得到的控制方程进行了数值求解，并与实验数据作了比较，发现二者具有较好的一致性。

本文研究了在平头圆柱体的冲击下，薄球形壳的动力大变形。通过等度量变换，给出了球壳的变形模态。在Perzyna和Symonds的粘塑性本构模型基础上。设材料服从Mises屈服条件，并假定弯矩和膜力不耦合。根据刚粘塑性强化材料的变分原理，给出球壳的运动方程。数值结果与实验进行了比较，二者吻合较好。

目的 研究球形塑性壳在撞击载荷作用下的动态破坏行为。方法　通过引入等度量变换，给出了球壳的变形模态;利用能量平衡给出了壳体在撞击载荷作用下大变形动态破坏的运动控制方程；采用Runge-Kutta方法求解了该运动控制方程。 结果　给出了冲击力，窝陷半径和中心点位移随时间的变化关系以及最大窝陷半径、最大中心点位移和最大冲击力随弹体速度的变化关系。结论　本文结果与实验结果有比较好的一致性。

This paper presents a theoretical analysis of the large deformation problem of a plastic spherical shell impacted by a missile. Firstly, a deformation mode of the spherical shell is given by introducing isometric transformation. Secondly, the large deformation problem of a rigid-plastic spherical shell is solved. A comparison between the theoretical results and the experimental ones indicates that the two groups of results are in conformity with each other.

On the basis of yon Karman equations and using the general bifurcation theory, the elastic instability of an orthotropic elliptic plate whose edge is subjected to a uniform plane compression is discussed. Following the well-known Liapunov-Schmidt process the existance of bifurcation solution at a simple eigenvalue is shown and the asymptotic expression is obtained by means of the perturbation expansion with a small parameter. Finally, by using the finite element method, the critical loads of the plate are computed and the post-buckling behavior is analysed. And also the effect of material and geome-tric parameters on the stability is studied.