基于奇异元计算分析裂纹尖端应力强度因子  

Analysis of Finite Element Model for Calculating Stress Intensity Factor Based on Crack-tip Singular Element

作　　者：陈景杰[1] 黄一[1] 刘刚[1] 

机构地区：[1]大连理工大学船舶工程学院,辽宁大连116024

出　　处：《中国造船》2010年第3期56-64,共9页Shipbuilding of China

摘　　要：采用两种奇异单元模拟裂纹尖端应力应变场的奇异性,建立了相应的计算裂纹尖端应力强度因子的ANSYS有限元模型。通过数值计算,分别考察了这两种有限元模型中裂纹尖端附近区域网格参数的变化对应力强度因子计算精度的影响,比较了应力强度因子对各个参数的敏感程度。发现采用20节点奇异元的有限元模型计算的应力强度因子几乎与网格参数无关,其计算结果更稳定可靠。该模型能够用于船舶及海洋工程结构中含裂纹构件的应力强度因子计算。In this paper,two kinds of crack-tip singular element are employed to describe the singularity of stress-strain field near the crack tip,and then the corresponding finite element models for calculating stress intensity factors at the crack tip are established by using ANSYS.In this numerical simulation,the influences of various grid parameters in the region near crack tips on the calculation accuracy of the stress intensity factors are investigated respectively for these two kinds of finite element models.Then the parameters’ sensitivity degrees to the stress intensity factors are investigated in detail.The stress intensity factor calculated by the finite element model with 20-node singular element has nothing to do with the variation of grid parameters,and the result is more stable and reliable.It is believed that this kind of finite element model is effective in calculating stress intensity factor of the cracked components in ship and ocean engineering structures.

关 键 词：船舶、船舶工程 应力强度因子 奇异单元 有限元模型 网格参数 

分 类 号：U661.4[交通运输工程—船舶及航道工程]