复合型三维裂纹应力强度因子计算方法的研究

Research to Calculate Stress Intensity Factor of Mixed-Mode Three-Dimensional Crack

对单元初始应力法应用于复合型三维裂纹问题进行了研究。基于有限元分析技术,利用近裂尖退化的1/4节点奇异单元最佳应力点的应力和坐标,对含有内埋倾斜圆形复合型三维裂纹的圆柱体在远场均布拉伸应力作用下的应力强度因子进行了计算。结果表明,与解析解相比,单元初始应力法计算的KI的最大相对误差为1.44%,KⅡ的最大相对误差为-2.30%,KⅢ的最大相对误差为-1.22%。单元初始应力法对于复合型三维裂纹应力强度因子的计算具有较强的实用性,且计算精度高。

An element initial stress method to calculate stress intensity factor of three-dimensional mixed-mode crack is introduced.Based on the finite element analysis techniques,a circular ramp crack buried inside a cylinder under far-field equal tensile force was calculated by this method.The degradation of the 1/4 node singular element was adopted,and the stress intensity factor was got from calculating the stress of the prime point stress about the crack tip.The relative error of the stress intensity factor of n...