摘要
采用水泥砂浆材料和充填材料模拟含缺陷岩石,分别对含孔洞、柔性充填物及刚性充填物试样进行低周疲劳试验,观察含缺陷试样的疲劳破坏特征,得出含缺陷试样的轴向不可逆变形阶段性规律,研究不同缺陷对岩石类材料的疲劳寿命、疲劳裂纹萌生及其扩展的影响。试验结果表明:循环荷载作用下含缺陷岩石试样的轴向不可逆变形经历初始变形、等速变形以及加速变形3个阶段;含缺陷试样疲劳裂纹首先在有较大应力集中的缺陷与基体材料界面边缘处萌生及扩展;在相同循环加卸载条件下,预制孔洞直径越大,对应的孔洞试样疲劳寿命越短;刚性充填物试样最容易发生疲劳破坏,孔洞试样次之,柔性充填物试样疲劳寿命最长。
Experimental study of failure characteristics of rock containing flaw under cyclic loading is carried out by using similarity materials. The similarity materials are elaborately designed by cement mortar and filling materials to simulate rocks with hole, flexible filling, or rigid filling. The characteristics of rocks containing flaw for the low-cycle fatigue damage are observed; and the three stages of the irreversible uniaxial deformation process are presented. Different defects in rock-like materials have great influence on their fatigue life and initiation and propagation of fatigue cracks. Experimental results show that the uniaxial deformation can be divided into three stages： initial deformation stage, constant-speed deformation stage, and acceleration deformation stage. Fatigue cracks are prone to initiate and propagate on the interface of defective and basis materials, where stress is concentrated. Conclusion can be made that with the same load conditions and the same sizes of flaw, the greater diameter of the hole is, the shorter fatigue life of hole-defect specimen is. It is also found that the fatigue lives of rigid-filling specimens are the shortest; the hole specimens take the second place; flexible-filling specimens have the longest life.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2009年第12期2490-2495,共6页
Chinese Journal of Rock Mechanics and Engineering
基金
高等学校博士学科点基金资助项目(200805330029)
教育部新世纪优秀人才计划资助项目(NCET–07–0860)
关键词
岩石力学
含缺陷岩石
循环荷载
低周疲劳
疲劳寿命
不可逆变形
疲劳裂纹扩展
rock mechanics
rock containing flaw
cyclic loading
low-cycle fatigue
fatigue life
irreversible deformation
fatigue crack propagation
