CAJ | 학술논문

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.
응용폭작가재적투사식동초산선측시계통,분석료유궤파리절조공폭파모형적렬문동태특정변화규률.비교료불동절조각도、절조심도적정향단렬렬문첨단적확전장도、확전속도화동태응력강도인자.초보탐토료절조폭파적동태효응,연구표명절조공폭파조기렬문파배모식위폭작랍응력파작용하적Ⅰ형쾌속확전렬문,렬문첨단랍응력집중적취적교대응변능유지료폭작렬문진일보확전,렬문첨단확전후기표현위P파、S파공동작용하적복합형확전특정.절조각위60°시획득적정향단렬효과최호,합리절조심도위포공반경적1/4～1/2.
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.