摘要:
利用爆炸加载动态焦散线测试系统,研究了双炮孔切槽方式下、同时起爆、两炮孔间贯穿裂纹和炮 孔外侧裂纹扩展的动态行为。实验结果表明:贯穿裂纹尖端并未直接相遇,而是一上一下,相遇后继续扩展, 并向异方已有的裂纹方向移近。裂纹扩展速度和加速度均呈现波浪起伏式的涨落变化。同一条裂纹扩展的 速度和加速度的峰值交替出现,加速度先达到峰值,速度再达到峰值。动态应力强度因子KⅠ 由最大值迅速 减小,然后经过反复振荡后,又逐渐增大,并达到第2个峰值,之后开始减小。裂纹扩展的过程中,KⅡ 基本都 小于KⅠ 。贯穿裂纹尖端的动态应力强度因子大于外侧裂纹的。动态能量释放率由最大值迅速减小,振荡变 化后第2次达到峰值,又逐渐减小。
Abstract:
Usingadynamiccausticsblastloadingsystem,thepaperstudiedthedynamicbehaviorof perforatedcrackpropagationbetweentwoholesandlateralcrackpropagationontheconditionofgroovingwithtwoboreholeblastingandsimultane usinitiation.Ascanbeseenfromtheresults,theperforatedcracktipsdidnotdirectlyencounter, butonewasatthetopandtheotherwasbelow,metand wentonpropagation,thengotclosertothedirectionoftheanisotropicexistingcrack.Thevelocity andaccelerationshowedatypeoffluctuationchangesaswave.Foronecrack,theaccelerationfirstly cametothepeak,thenthevelocitycametothepeak.ThedynamicstressintensityfactorKⅠ decreasedrapidlyfromthemaximum, oscillated,anduptothesecondpeak,thendecreased.KⅡ was almostsmallerthanKⅠ .Thestressintensityfactoroftheperforatedcracktipwasalmostgreater thanthatofthelateralcrack.Thedynamicenergyreleaseratedecreasedrapidly,oscillated,andthen decreased.
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