Ⅰ-Ⅱ型裂纹发展的剪应力准则研究  

Researches on Shear Stress Criterion of Ⅰ-Ⅱ Fracture Expansion

作　　者：曾国柱[1] 张世雄[2] 齐添[1] 刘干斌[3] 

机构地区：[1]广州穗监工程质量安全检测中心,广州510150 [2]武汉理工大学资环学院,武汉430070 [3]宁波大学建筑工程与环境学院,宁波315211

出　　处：《工程地球物理学报》2009年第1期43-47,共5页Chinese Journal of Engineering Geophysics

基　　金：浙江省科技计划支撑项目(编号:2008C31030)资助

摘　　要：将Ⅰ-Ⅱ型裂纹表面的剪应力引入裂尖应力强度因子的计算,获得了含中心闭合裂纹在不同裂纹长度、倾角以及摩擦系数下裂纹尖端的应力强度因子值。引入等径向剪应力线rτθ这一概念,在预测裂纹发生临界扩展时提出以下两个假设:闭合裂纹将沿着等rτθ线上双剪应力和最小的方向扩展;裂纹尖端的应力强度因子KⅡ达到材料的临界值KⅡC,裂纹将开始扩展;建立了Ⅰ-Ⅱ型闭合裂纹的剪应力准则。利用所建立的断裂判据计算求得的临界起裂角cθ与各种经典复合型断裂准则计算裂纹起裂角的结果较为接近,将其应用于Ⅰ-Ⅱ型裂纹的断裂判定是安全的。Surface effective shear stress of closed--crack into calculating the stress intensity factor（SIF） was introduced, Values of SIF were then given when cracks were in different length, different angle and different friction coefficient. Introducing the concept ofiso--τrθ line, two assumption were presented when predicting critical fracture of crack： the crack grew up along the direction in which the sum of twin shear stress reached minimum at iso -τrθline; the crack began to grow when the crack tip stress intensity factor KⅡarrived at critical value KⅡc. Accordingly, effective shear stress criterion for closed--crack was proposed. Critical cracking angle θc of closed--crack was calculated using the criterion.

关 键 词：Ⅰ-Ⅱ型裂纹 应力强度因子 剪应力 断裂准则 

分 类 号：P631[天文地球—地质矿产勘探]