三维表面裂纹相互作用扩展贯通机制试验研究.pdfVIP

第26 卷 第9 期 岩石力学与工程学报 Vol.26 No.9 2007 年9 月 Chinese Journal of Rock Mechanics and Engineering Sept. ，2007 三维表面裂纹相互作用扩展贯通机制试验研究 黄明利1，黄凯珠2 (1. 北京交通大学 土木建筑工程学院，北京 100044 ；2. 香港理工大学 土木与结构工程系，香港) 摘要：通过对用机械法预制多个硬币状裂纹的冷冻有机玻璃材料进行单轴加载系列试验，研究脆性材料三维表面 裂纹扩展演化和贯通机制。研究结果表明，三维裂纹间的相互作用对裂纹萌生和扩展主要有两种影响，即相互促 进或彼此抑制，裂纹演化过程中其空间位置起主要作用。三维表面裂纹间的贯通要复杂得多，同时受裂纹切割深 度、空间位置影响较大。这一研究加深了对有机玻璃材料(PMMA)等透明脆性材料破坏机制的了解，同时对岩石 材料破坏机制的研究也大有裨益。 关键词：岩石力学；三维裂纹；扩展贯通；脆性材料 中图分类号：TU 45 文献标识码：A 文章编号：1000 –6915(2007)09 –1794 –06 EXPERIMENTAL STUDY ON PROPAGATION AND COALESCENCE MECHANISMS OF 3D SURFACE CRACKS 1 2 HUANG Mingli ，WONG R H C (1. School of Civil Engineering and Architecture，Beijing Jiaotong University ，Beijing 100044 ，China； 2. Department of Civil and Structural Engineering ，Hong Kong Polytechnic University ，Hong Kong ，China) Abstract ：A series of uniaxial compressive tests on the frozen PMMA with pre-existing 3D cracks were performed in laboratory to investigate the mechanisms of crack propagation and coalescence in brittle materials. It is found that for 3D surface cracks ，the interactions of cracks affect crack growth and extension in two aspects ，i.e. the interaction either prompting crack extension or restraining it. The mechanism of crack interaction depends mainly on the location of cracks in spatial domain. The propagation and coalescence of 3D surface cracks are dependent on the crack depth and the crack configuration. The test results are helpful to more understanding of the failure mechanism of brittle materials including PMMA and also to the study of the failure mechanism of rock under loading.