多裂纹相互作用下断裂行为的边界元分析  

Boundary Element Analysis of Fracture Behavior under the Interaction of Multi-cracks

作　　者：黄祎丰 裘进浩[1] 郭志强 HUANG Yi-feng;QIU Jin-hao;GUO Zhi-qiang(State Key Laboratory of Mechanics&Control of Mechanical Structures,Nanjing University of Aeronautics and Astronatics,Nanjing 210016,China;Beijing Aircraft Strength Institute,Beijing 100083,China)

机构地区：[1]南京航空航天大学机械机构力学控制国家重点实验室,南京210016 [2]北京飞机强度研究所,北京100083

出　　处：《科学技术与工程》2018年第8期6-12,共7页Science Technology and Engineering

基　　金：国家自然科学基金(50135010)资助

摘　　要：基于边界元法,数值计算含多裂纹有限板在拉伸载荷下的断裂参数。利用裂纹面边界单元节点的张开位移,并结合线性拟合外推的方法计算应力强度因子。综合考虑计算精度和计算效率,讨论并选定合适的边界单元划分密度和类型。按照最大周向应力准则,通过断裂参数等效应力强度因子和扩展方向,分析裂纹I和II型复合断裂行为。裂纹间的相互作用会抑制或增强断裂行为,通过多个算例考查多裂纹的角度、长度、分布位置和间距等因素对抑制和增强作用的影响。Fracture parameters of a finite plate with multiple cracks under tensile loading were numerically investigated by boundary element method.Linear fitting extrapolation was applied to calculate the stress intensity factor,which was based on the opening-displacement of the boundary element nodes on crack surface.Selection of boundary element type and size was also discussed by taking into consideration of the accuracy and efficiency of calculation.Based on the maximum circumferential stress criterion,composite fracture behaviors of type I and type II were analyzed respectively by using the equivalent stress intensity factor and the extension direction.The interaction between cracks will inhibit or enhance the fracture behavior.Therefore,the factors concluding the angle length,location and spacing of multi-cracks,which effect on the inhibition and enhancement,were researched by several examples.

关 键 词：多裂纹 边界元法 应力强度因子 张开位移 

分 类 号：O346.1[理学—固体力学]