冲击载荷下含表面裂纹圆柱壳体的动态断裂

Dynamic Fracture of Impacted Hollow Cylinder with Semi-Elliptic Surface Crack

动态载荷下含表面裂纹的有限尺寸构件的断裂问题在工程实践中有着重要意义,但由于此类问题非常复杂,目前还不能求得解析解。本文针对含轴向半椭圆盘状表面裂纹的圆柱壳体,应用有限元法研究了动态载荷下其断裂问题,计算了动态应力强度因子与静态应力强度因子的比值KdIyn(t)/KsIta。从计算结果可以得出,比值KdIyn(t)/KsIta与结构和裂纹的尺寸有关,而与冲击载荷的大小无关。本文所得结果在一定程度上揭示了圆柱壳体表面、裂纹面、物质惯性和弹性波的相互作用及其对动态断裂的影响。

It is difficult of obtain the analytic solutions for dynamic fracture of finite-sized components with crack under impact loading due to itself inhererent complexity.Aiming at a impacted hollow cylinder with a semi-elliptic surface crack,three-dimensional finite element program is developed to determine the crack tip displacement and dynamic stress intensity factor.The results show that the ratio of K^(dyn)_I(t)/K^(sta)_I is related to the sizes of the structure and crack,but independent on the loaded impact amplitude.The interactions of hollow cylinder boundary surface,crack surface,material inertia with elastic wave propogation are revealed simultameously.