大曲率缺口奇异有限元计算模型及其数值分析

A Singular Finite Element Modelling of Blunt Crack Problems and Numerical Analysis

研究了大曲率缺口的位移场基本理论,构造了一种新的大曲率缺口位移模式;建立含大曲率缺口损伤结构有限元方程和相应的缺口奇异单元;提出了求解大曲率缺口应力与应力强度因子等断裂参量一种的新数值计算方法。算例说明本方法是一种有效的数值计算分析方法,其研究成果对众多的材料破坏试验极有参考价值。

Basic theory of displacement field in the blunt cracks is studied and a new displacement modelling of blunt crack is constructed. A finite element equation with a blunt crack is built, the new singular element at the end of a blunt crack is given and a new method for calculating stress intensity factors of blunt crack problems is presented. Solutions obtained with present method are good in agreement with those of theoretical solutions. With the different selections of the Gauss's points and structural dimensions, the calculating results with the present method are stable, reliable and highly accurate. The present method is easy to use in practical program operation. Numerical examples are given to illustrate the validity of the present method.