裂隙分支对单轴拉伸下裂纹破坏模式的影响  

Effect of Fissure Branches on Crack Failure Modes Under Uniaxial Tension

作　　者：张端[1] 董茜茜 ZHANG Duan;DONG Qianqian(Hebei University of Technology,Tianjin 300401,China)

机构地区：[1]河北工业大学,天津300401

出　　处：《矿业研究与开发》2020年第11期64-70,共7页Mining Research and Development

基　　金：国家自然科学基金项目(51808185)。

摘　　要：为研究裂隙分支的存在对单轴拉伸下裂纹破坏模式的影响,使用3D打印技术制备含不同形状的弯折、Y型裂隙试样进行试验,并通过数值方法对裂隙尖端应力强度因子及裂纹扩展进行模拟。结果表明:弯折裂隙的破坏存在尖端与非尖端两种模式,其起裂角在尖端破坏模式下先减小再增大;Y型裂隙的破坏模式和起裂角都与主裂隙倾角有关,在相同主裂隙倾角下,起裂角因分支裂隙倾角的增加存在明显变化;两类裂隙的起裂载荷均随分支长度的增加而减小。弯折裂隙中应力强度因子与分支裂隙倾角关系曲线的形状较复杂,且曲线随分支长度的增加曲率变大;Y型裂隙中较长的分支裂隙的应力强度因子大于较短的。使用RFPA 2D进行的裂纹扩展模拟结果与试验结果非常吻合。In order to explore the effect of fissure branches on crack failure modes under uniaxial tension,3 Dprinting technology was used to prepare kinked and Y-type fissures samples with different shapes for testing.Stress intensity factor and crack propagation at the crack tip were simulated by numerical methods.The results show that there are two failure modes of kinked fissures,namely tip failure and non-tip failure.The initial angle decreases first and then increases in the tip failure mode.The failure mode and initial angle of the Y-type fissures are related to the inclination angle of the main fissure,and the initial angle changes significantly with the increase of the inclination angle of branch fissure under the same inclination angle of main fissure.The initial load of both types of fissures decreases with the increase of the branch fissure length.Curve shapes of the relationship between stress intensity factor and inclination angle of the branch fissure are complex,and the curvature increases with the increase of the branch length.Stress intensity factor of the longer branch fissure in the Y-type fissures is larger than that of the shorter branch fissure.Finally,the simulation results of crack propagation obtained by RFPA 2 Dare in good agreement with the experiments results.

关 键 词：弯折裂隙 Y型裂隙 应力强度因子 起裂荷载 起裂角度 裂纹扩展 

分 类 号：TD313[矿业工程—矿井建设]