爆生气体驱动双共线Ⅰ型裂纹的扩展行为  

Propagation behavior of two collinear modeⅠcracks driven by explosive gas

作　　者：杨立云[1] 董鹏翔 王启睿 王青成 Yang Liyun;Dong Pengxiang;Wang Qirui;Wang Qingcheng(School of Mechanics and Civil Engineering,China University of Mining and Technology-Beijing,Beijing 100083,China;Department of Civil Engineering,Tsinghua University,Beijing 100084,China)

机构地区：[1]中国矿业大学(北京)力学与建筑工程学院,北京100083 [2]清华大学土木工程系,北京100084

出　　处：《矿业科学学报》2023年第4期538-547,共10页Journal of Mining Science and Technology

基　　金：国家自然科学基金(51974316);中央高校基本科研业务费-重点领域交叉创新项目(2022JCCXLJ01)。

摘　　要：在光面预裂爆破中相邻炮孔间的共线裂纹相向扩展时会先互相排斥后相互吸引,裂纹扩展路径呈“勾连”状现象。为解释这一现象,基于T应力修正后的最大拉应力准则,联合Abaqus软件与Hypermesh软件研究了爆生气体驱动相向扩展的双共线Ⅰ型裂纹的起裂和扩展行为。结果表明:模型尺寸(模型宽度W与高度H的比值)、初始裂纹尺寸(初始裂纹长度a和圆孔半径r的比值)和裂纹面上爆生气体压力对裂纹起裂行为的影响显著,Ⅰ型裂纹扩展中裂纹扩展路径出现“勾连”状现象的先决条件是“Ⅰ型裂纹起裂时或扩展中发生偏转”;裂纹面上的爆生气体减弱了Ⅰ型裂纹扩展中发生偏转的程度,使裂纹扩展路径更难出现呈“勾连”状的现象。通过裂纹增量扩展法模拟了裂纹扩展路径,Ⅰ型裂纹扩展会产生“勾连”状的裂纹扩展路径;裂纹扩展路径呈“勾连”状的现象与裂纹间的相互作用有关,该相互作用可通过裂纹扩展角θ的正负来表示。In smooth pre-splitting blasting,two collinear cracks extending opposite to each other between adjacent holes will first avoid each other and then attract each other,resulting in crack propagation path that often presents hooked or butterfly-shaped loops.Based on the maximum tensile-stress criterion modified by T-stress,this study probed into the crack propagation behavior of two collinear modeⅠcracks extending opposite to each other by using Abaqus and Hypermesh.The numerical results indicated that model size(ratio of model width to height:W/H),crack length(ratio of initial crack length to circular hole radius:a/r)and pressure distribution of explosive gas on crack surface have a significant effect on crack growth behavior.Deflection occurs during the propagation of mode I crack,which makes the crack propagation path presents hooked loops.The explosive gas on the crack surface reduces the degree of deflection in mode I crack propagation,and makes it more difficult for the crack growth path to show“hooking”phenomenon The crack propagation path is simulated by the method of incremental crack propagation and the results show that the crack propagation path of mode I crack does present hooked loops.The phenomenon of“hooking”of crack propagation path is related to the interaction between the cracks,which can be represented by the crack growth angleθ.

关 键 词：T应力 爆生气体 裂纹扩展 双裂纹 数值模拟 

分 类 号：O346.1[理学—固体力学]