基于应变片法的非平行多裂纹相互作用及起裂机理  

Interaction and initiation mechanism of non-parallel multiple cracks by strain gauge method

作　　者：沈晴晴 黄典一 饶秋华[1] 易威 孙栋良 李卓[1] Qing-qing SHEN;Dian-yi HUANG;Qiu-hua RAO;Wei YI;Dong-iang SUN;Zhuo LI(School of Civil Engineering,Central South University,Changsha 410075,China;College of Civil and Construction Engineering,Hunan Institute of Technology,Hengyang 421002,China)

机构地区：[1]中南大学土木工程学院,长沙410075 [2]湖南工学院土木与建筑工程学院,衡阳421002

出　　处：《Transactions of Nonferrous Metals Society of China》2024年第5期1655-1668,共14页中国有色金属学报（英文版）

基　　金：National Natural Science Foundation of China(Nos.51874351,52078495);Hunan Institute of Technology Introduced Talents Research Start-up Fund Project,China(No.HQ22016)。

摘　　要：通过计算3条非平行斜裂纹的最大应力强度因子KⅠ,kmax(θ)和KⅡ,kmax(θ),揭示其相互作用机理,并采用多裂纹起裂准则预测非平行多裂纹的起裂参数。对含3条非平行斜裂纹的红砂岩试样开展单轴压缩试验,采用应变片测量方法监测裂纹尖端附近的应变,以确定裂纹起裂顺序。结果表明:裂缝相对倾角的变化对破坏轨迹影响不大且多裂纹尖端很少同时起裂。单轴压缩下含3条非平行斜裂纹红砂岩试件破坏形式可分为两种:翼裂纹贯通和翼裂纹-次生裂纹贯通。断裂机理均为Ⅰ型(拉伸)起裂。预测结果与试验结果吻合较好,验证了理论结果的有效性。The maximum stress intensity factors,KI,kmax(θ)and KII,kmax(θ),of three non-parallel oblique cracks were calculated to reveal the interaction mechanism of multiple cracks.The multiple crack initiation criterion was adopted to predict the non-parallel multiple crack initiation parameters.Uniaxial compression tests were performed on rock specimens(red sandstone)with three non-parallel oblique cracks,where the strain near the crack tips was monitored by the strain gauge measurement method to determine the crack initiation sequence.The results showed that the change of crack relative inclination angle had little effect on the fracture trajectory.Multiple crack tips were seldom initiated at the same time.The failure modes of red sandstone specimens with three non-parallel oblique cracks under uniaxial compression are divided into two types:wing crack penetration and wing crack-secondary crack penetration.All of the fracture mechanisms are Mode I(tensile)initiation.The predicted results coincided well with the test results,verifying the validity of the theoretical results.

关 键 词：非平行多裂纹 相互作用机理 起裂机理 应变片法 

分 类 号：TD315[矿业工程—矿井建设]