本文建立了采用20节点奇异元1/4节点位移法求解三维裂纹整个前缘3种类型应力强度因子的数值计算方法，给出了裂纹网格划分方法以及网格划分参数取值范围；基于平板表面裂纹研究了网格划分参数对应力强度因子计算结果的影响，并与Newman-Raju解析公式计算结果对比验证了数值方法的准确性，二者最大误差小于2%；采用数值计算方法计算了裂纹扩展标准三点弯曲样扩展过程中单边穿透裂纹前缘应力强度因子，并与解析公式计算结果进行对比分析，二者最大误差为4.7%，且随着裂纹扩展，误差越来越小。结果表明，提出的数值方法可用于含裂纹结构整个裂纹前缘不同类型应力强度因子求解中。
This paper proposed an effective finite element method for calculating stress intensity factor of 3D crack front using 20-node singularity element and quarter point displacement method. The surface cracked plate SIF calculation has been carried out by numerical method and Newman-Raju formula. The effect of crack front mesh parameters on the SIF results of the whole surface crack front were discussed. The results indicate that the calculation result of the proposed method is stable and the relative errors are within 2%. The SIF results of the SE(B) specimen single edge crack have been calculated by the numerical method with a maximum 4.7% error compared with the analytical solution results. The method proposed herein can be used in the calculation of KI, KⅡ, KⅢ for cracked structures.
2019,41(2): 9-13 收稿日期：2018-06-30
DOI：10.3404/j.issn.1672-7649.2019.02.002
分类号：O342
基金项目：国防预研项目资助项目（3020503010101）
作者简介：黄如旭(1987-),男,工程师,研究方向为船舶与海洋工程结构疲劳与断裂理论、实验及数值模拟
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