切槽孔爆破动态力学特征的动焦散线实验  

Experimental investigation on dynamic mechanical behaviors of cracks induced by V-notch borehole blasting with dynamic caustics

作　　者：李清[1] 王平虎[1,2] 杨仁树[1] 田晓冰[1] 韩伟光[1] 张二蒙[1] 

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]晋城无烟煤矿业集团有限公司寺河矿,山西晋城048000

出　　处：《爆炸与冲击》2009年第4期413-418,共6页Explosion and Shock Waves

基　　金：国家自然科学基金项目(50774086);国家863计划目标导向项目(2007AA06Z131)

摘　　要：应用爆炸加载的透射式动焦散线测试系统，分析了有机玻璃切槽孔爆破模型的裂纹动态特征变化规律。比较了不同切槽角度、切槽深度的定向断裂裂纹尖端的扩展长度、扩展速度和动态应力强度因子。初步探讨了切槽爆破的动态效应，研究表明切槽孔爆破早期裂纹破坏模式为爆炸拉应力波作用下的I型快速扩展裂纹，裂纹尖端拉应力集中积聚的较大应变能维持了爆炸裂纹进一步扩展，裂纹尖端扩展后期表现为P波、S波共同作用下的复合型扩展特征。切槽角为60°时获得的定向断裂效果最好，合理切槽深度为炮孔半径的1／4～1／2。Using the transparent material PMMA, a model experiment was carried out by the transmitted dynamic caustics to obtain a series of dynamic caustic photos. By the experimental results, the directional fracture characteristics of crack tips, such as dynamic stress intensity factors, expanding lengths and velocities, were discussed for different notch angles and depths. In addition, dynamic effects in V-notch blasting were explored according to the discussed results. It is shown that the cracks are subjected to tensile （mode-I） loading to rapidly expand at the initial stage of the V-notch blasting and later the crack tip propagation is affected by the combined action of P and S waves （complex mode）. And the appropriate V-notch angle and notch depth was obtained to control the directional fracture.

关 键 词：爆炸力学 裂纹扩展 动焦散线 切槽爆破 动态效应 

分 类 号：O384[理学—流体力学] TD235.1[理学—力学]