【作者】 朱维申； 郭彦双； 李术才； 林春金； 温暖冬； 杨磊；

【Author】 ZHU Wci-shen GUO Yan-shuang LI Shu-cai LIN Chun-jin WEN Nuan-dong YANG Lei (Geotechnical & Structural Engineering Research Center,Shandong University,Ji’nan,250061,China)

【机构】 山东大学岩土与结构工程研究中心；

【摘要】 采用类岩石材料研究了含边裂纹试样在三点弯曲加栽条件下的裂纹扩展过程,并利用声发射(AE) 测试技术分析了含裂隙试样弯拉应力作用过程中预制裂纹萌生、起裂、扩展和断裂破坏的全过程的声发射特征．试验结果表明,声发射的阶段性突发特征反映了张拉裂纹阶段性扩展的规律,但边裂纹的拉破裂特征不同于压剪应力作用下的声发射特征．预制裂纹在拉破裂过程中的声发射特征表现为 AE 数的渐进增长、快速增长、突发式增长和逐渐下降4个阶段．声发射源的带状分布规律表明,在弯拉应力作用下,裂隙的张性断裂不是孤立的,而是有若干个小断裂面聚集而成宏观断裂,探讨了预制裂隙受拉破坏的内在机理。更多还原

【Abstract】 Under three points bending loading,some experiments of flaw growth using special mortar specimen with single edge flaw are carried out.The whole process of initiation,cracking,growth and fracture for pre-existing flaw is analyzed by using acoustic emission(AE)technique.Experimental results show that the AE properties of tensile fractures are different from the ones of fracture induced from compressive stress.The AE properties of flaw propagation process under bending action contain four stages:gradual increment,quick increment,sudden increment and gradual decrement of AE numbers.The distribution pattern of the AE sources is strip shape;it shows that tensile fracture for edge flaw is made of many micro cracks,but single fracture.The failure mechanism of tensile crack is explained.更多还原