三孔定向爆破作用下的空孔效应实验研究  

Empty Hole Effect under Three-borehole Directional Blasting Load

作　　者：王思嘉[1] 王煦[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

出　　处：《科学技术与工程》2016年第35期1-5,14,共6页Science Technology and Engineering

摘　　要：为得到三孔定向爆破作用下空孔对爆生主裂纹扩展过程的影响规律,采用动态焦散线法进行实验,研究了不含空孔和含空孔情况下爆生裂纹的动态应力强度因子、扩展轨迹及扩展速度的变化规律。研究结果表明:空孔对爆生裂纹扩展轨迹的导向作用十分明显。无空孔时,爆生裂纹的扩展速度震荡幅度较大;有空孔时,爆生裂纹的扩展速度震荡幅度较小。无空孔时,三条爆生裂纹在相互贯通之前,裂尖的动态应力强度因子会突然增大,然后迅速下降;有空孔时,爆生裂纹与空孔贯通前,其动态应力强度因子则稳定在一定范围内震荡。For purpose of investigating the influence of the hole on the propagation process of the blast-induced main crack under the three-borehole directional blasting load,dynamic caustic method was used to study the evolutions of the dynamic stress intensity factor（ DSIF）,growth path and propagation velocity of the blast-induced crack with an empty hole and non-hole situations respectively. The experimental results show as follows： the guiding effect on the growth of blast-induced crack is significant with the existence of the hole. The crack propagation velocity oscillates with higher amplitude for non-hole situation than that with a hole in the specimen. For non-hole situation,the DSIFs of the crack tips witnesses a sudden increase before the coalescence of the three blast-induced cracks,and then decline dramatically. However,for the specimen with a hole,the DSIFs are able to oscillate within a certain range before the meeting of the blast-induced crack and the hole.

关 键 词：动态焦散线 空孔效应 爆炸荷载 动态应力强度因子 

分 类 号：O348.1[理学—固体力学]