含单裂纹带圆孔板单轴破坏试验及仿真  

Uniaxial failure test and simulation of plate with circular hole containing single crack

作　　者：经来旺[1] 彭绍驰 李学帅 李树文 严悦 经纬[1] JING Laiwang;PENG Shaochi;LI Xueshuai;LI Shuwen;YAN Yue;JING Wei(School of Civil Engineering and Architecture,Anhui University of Science and Technology,Huainan 232001,China)

机构地区：[1]安徽理工大学土木建筑学院,安徽淮南232001

出　　处：《中国矿业》2022年第7期174-182,共9页China Mining Magazine

基　　金：安徽省青年科学基金项目资助(编号:51904012);安徽省高等学校自然科学研究重点项目资助(编号:KJ2019A0099);安徽省博士后研究人员科研活动经费资助项目资助(编号:2018B268)。

摘　　要：为了研究含不同预制裂纹长度及倾角下的单裂纹带圆孔板单轴应力状态下的裂纹扩展状况,分别制作裂纹倾角为0°、15°、30°、45°、60°、75°、90°,裂纹长度为7.5 mm、12.5 mm、17.5 mm的带直径为15 mm圆孔的类岩石试件,利用DDL-200型试验机进行单轴压缩试验,并使用颗粒流离散元软件PFC对试件应力状态和裂纹扩展做进一步研究。结果表明:合理的预制裂纹能够提高试件的抗压强度,并且随着裂纹倾角的增加,试件应力集中逐渐从裂纹尖端过渡至孔边,使得新裂纹的萌生和扩展向孔边转移,同时,较大的裂纹长度和较小的裂纹倾角使得试件有更大的受拉区域面积和更加不均匀的应力分布;此外,应力强度因子随着裂纹倾角的增大呈先减小后增大的变化规律,降低阶段和上升阶段所对应的裂纹分别属于闭合型和张开型。该研究成果可为地下工程中的巷道支护和切顶卸压提供一定的参考。In order to study the crack propagation of a circular perforated plate with a single crack under uniaxial compression with different crack lengths and crack angles, rock-like specimens with a circular hole diameter of 15 mm are made, in which the crack lengths are 7.5 mm, 12.5 mm and 17.5 mm respectively, and the crack angles are 0°,15°,30°,45°,60°,75° and 90° respectively, the uniaxial compression test is carried out by DDL-200 testing machine, the particle flow discrete element software PFC is used to further study the stress state and crack propagation of the specimen.The results show that appropriate prefabricated cracks can improve the compressive strength of specimens, with the increase of crack inclination, the stress concentration of the specimen gradually transits from the crack tip to the hole edge, making the initiation and propagation of new cracks transfer to the hole edge, at the same time, larger crack length and smaller crack inclination make the specimen have larger tensile area and more uneven stress distribution.In addition, the stress intensity factor decreases first and then increases with the increase of crack inclination, the crack corresponding to the lowering stage belongs to the closed crack, and the crack corresponding to the rising stage belongs to the open crack.The research results can provide some reference for roadway support and roof cutting pressure relief in underground engineering.

关 键 词：预制裂纹 裂纹扩展 单轴破坏 应力强度因子 PFC 

分 类 号：TD315[矿业工程—矿井建设]