爆炸荷载下不对称Y型裂纹扩展规律的试验研究

发布时间：2018-01-26 13:09

本文关键词： Y型裂纹爆炸荷载动焦散裂纹扩展动态应力强度因子　出处：《岩土力学》2017年08期 　论文类型：期刊论文

【摘要】：采用爆炸加载透射式动焦散测试系统,研究了爆炸荷载下不对称Y型裂纹扩展的动态行为。试验结果表明:爆炸荷载下两相向运动裂纹在相遇前裂纹尖端奇异场相互影响,焦散斑扭曲,裂纹尖端应力场改变,相遇前沿偏离水平方向相向扩展,偏离角度逐渐增大,相遇后偏离角度逐渐减小并朝对方已有裂纹方向扩展;两分支裂纹相交于主裂纹,翼裂纹主要从与入射应力波夹角较小和长度较长的分支裂纹起裂,沿周向最大拉应力垂直方向扩展;入射应力波夹角较小和长度较长的分支裂纹对入射应力波夹角较大和长度较短的分支裂纹扩展及其尖端应力强度因子有抑制作用;分支裂纹尖端动态应力强度因子均值随分支裂纹与应力波夹角增大而减小,分支翼裂纹扩展速度呈现振荡式变化规律。研究结果为实际工程中分析相互贯通裂纹的扩展规律提供了可靠依据。
[Abstract]:An explosive loading transmission dynamic caustic testing system is used. The dynamic behavior of asymmetric Y-mode crack propagation under explosive loading is studied. The experimental results show that the singularity field at the crack tip of two phase moving cracks under explosive load affects each other and the focal speckle is distorted. When the stress field at crack tip changes, the contact front propagates from the horizontal direction, the deviation angle increases gradually, and the deviation angle decreases gradually and propagates towards the direction of the existing crack. The two branch cracks intersect with the main crack, and the wing crack mainly starts from the branch crack with the smaller angle of incident stress wave and longer length, and propagates along the vertical direction of the maximum tensile stress in the circumferential direction. The branch crack with smaller angle and longer length of incident stress wave can inhibit the propagation of branch crack and the stress intensity factor at the tip of the crack with larger angle and shorter length of incident stress wave. The mean value of the dynamic stress intensity factor at the tip of the branch crack decreases with the increase of the angle between the branch crack and the stress wave. The experimental results provide a reliable basis for analyzing the propagation law of interpenetrating cracks in practical engineering.
【作者单位】：中国矿业大学(北京)力学与建筑工程学院;安徽理工大学化学与工程学院;
【基金】：国家自然科学基金面上项目(No.51274203,No.51374210) 高等学校学科创新引智计划资助(No.B14006)~~
【分类号】：TU751.9
【正文快照】： 在爆破工程中,被爆介质含有大量节理、裂隙、层理等缺陷,这些缺陷会分叉和贯通,表现出显著的非续性、各向异性和不均匀性。爆破时缺陷介质对应力波传播和爆生裂纹扩展有显著影响,严重影响爆破效果。因此,研究爆炸荷载下岩体节理裂隙动态力学性质和应力波传播规律一直是国内外

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