双孔爆炸应力波作用下缺陷介质裂纹扩展的动焦散试验
利用爆炸加载数字激光动态焦散线试验系统（DLDC）,研究了两切槽炮孔爆破爆生主裂纹和由预制缺陷尖端衍生的次裂纹扩展的动态力学行为。研究结果表明,两切槽炮孔同时起爆后,爆生主裂纹没有相互交汇贯通而是止于预制裂纹断面处,表明缺陷对定向断裂控制爆破效果有着重要的影响;次裂纹与主裂纹并没有直接贯通,而是呈＂勾连状＂的止于对方裂纹面上。与水平预制缺陷相比,垂直预制缺陷对主裂纹的扩展影响更大,其次裂纹在拉伸应力场的作用下而以I型扩展;当膨胀P波与运动着的裂纹相互作用时,裂纹扩展速度和裂尖动态应力强度因子都减小。...
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| Published in | 煤炭学报 no. 7; pp. 1755 - 1761 |
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| Main Author | |
| Format | Journal Article |
| Language | Chinese |
| Published |
2016
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| Subjects | |
| Online Access | Get full text |
| ISSN | 0253-9993 |
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| Summary: | 利用爆炸加载数字激光动态焦散线试验系统（DLDC）,研究了两切槽炮孔爆破爆生主裂纹和由预制缺陷尖端衍生的次裂纹扩展的动态力学行为。研究结果表明,两切槽炮孔同时起爆后,爆生主裂纹没有相互交汇贯通而是止于预制裂纹断面处,表明缺陷对定向断裂控制爆破效果有着重要的影响;次裂纹与主裂纹并没有直接贯通,而是呈＂勾连状＂的止于对方裂纹面上。与水平预制缺陷相比,垂直预制缺陷对主裂纹的扩展影响更大,其次裂纹在拉伸应力场的作用下而以I型扩展;当膨胀P波与运动着的裂纹相互作用时,裂纹扩展速度和裂尖动态应力强度因子都减小。 |
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| Bibliography: | blasting of double holes; defective medium; crack propagation; caustics; dynamic stress intensity factor The dynamic behavior of blast-induced cracks propagation between two notched boreholes in PMMA material with prefabricated crack under blasting load was studied by a new digital laser experimental system of dynamic caustics. The experimental results show that 1 in the simultaneous blasting process for the double notched boreholes,the interaction between the prefabricated crack and the blast-induced main crack interdicts the propagation of blast-induced main crack and the coalescence of two blast-induced main cracks,which indicates that the prefabricated crack has great influence on the directional fracture controlled blasting; 2 the blast-induced secondary cracks generated at the tips of horizontal prefabricated crack and the blast-induced main cracks do not meet directly in the propagating process,but move to the near blast-induced main crack surface,which leads to blast-induced secondary cracks growth in |
| ISSN: | 0253-9993 |