Ⅲ型裂纹断裂韧性测试及数值分析  

TEST AND NUMERICAL ANALYSIS OF FRACTURE TOUGHNESS MODEL Ⅲ FRACTURE

作　　者：黎立云[1] 宁海龙[1] 许凤光[2] 王建强[1] 李海云[1] 侯兰英[1] 

机构地区：[1]中国矿业大学力学与建筑工程学院,北京100083 [2]北京科技大学应用科学学院,北京100083

出　　处：《岩石力学与工程学报》2006年第12期2523-2528,共6页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家重点基础研究发展规划(973)项目(2002CB412705);国家自然科学基金资助项目(40472145)

摘　　要：设计测试岩石III型断裂韧性的试件及装置,测得比较稳定的花岗岩及大理石的III型断裂韧度。同时,也实测铸铁和低碳钢的III型断裂韧性,并对两类材料测试结果进行比较。通过断裂力学及有限元技术对试件III型裂纹应力场进行分析,得出裂纹尖端应力场第一主应力与剪应力的比值σ1/τzθ随裂纹深度δ的变化关系。从而揭示随裂纹深度δ的增加,III型裂纹破裂面将由螺旋面向直剪面变化的原因。An experimental apparatus to test the rock fracture toughness values of model Ⅲ fracture is designed; and the new kind of rock sample adapted to the apparatus is also designed. A series of stable fracture toughness values of model Ⅲ fracture in granite and marble are achieved by the experiments. At the same time, the fracture toughness values of model Ⅲ fracture in cast iron and mild steel are also obtained. The comparison between test results of the two kinds of materials is given. According to the analysis with fracture mechanics and finite element method, the stress fields near mold III fracture tip are obtained. The relationship of σ1/τzθ vs. the crack depth 8is achieved. Thus, the reasons that the fracture surface varies from helicoids to plane shearing surface with the crack depth 8aggrandizing gradually in model Ⅲ fracture are revealed.

关 键 词：岩石力学 Ⅲ型裂纹 螺旋面破坏 平面剪切破坏 数值分析 

分 类 号：TU452[建筑科学—岩土工程] O241[建筑科学—土工工程]