摘要: |
针对岩石材料的断裂力学问题阐述扩展有限元法的单元位移模式的选择、确定平面裂纹空间位置的水平集法和特殊单元的数值积分方法。介绍最大周向应力裂纹扩展判据和计算应力强度因子的相互作用积分法,进而建立岩石断裂力学的扩展有限元法。建立Ⅰ型裂纹和Ⅱ型裂纹的岩石断裂力学的扩展有限元计算模型,对I裂纹的应力强度因子和Ⅱ型裂纹的裂纹扩展路径进行扩展有限元法数值模拟计算。结果表明,建立的岩石断裂力学扩展有限元法可对岩石材料的断裂力学参数和裂纹扩展路径进行数值模拟分析,验证了数值计算结果的合理性,能有效地描述岩石断裂力学特性。 |
关键词: 扩展有限元法 水平集法 应力强度因子 相互作用积分法 裂纹扩展判据 裂纹扩展路径 |
DOI:10.3969/j.issn.1673-5005.2016.04.016 |
分类号::O 346.1 |
文献标识码:A |
基金项目:国家自然科学基金项目(11472309);中石油重大专项(2012-ZG-002) |
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Extended finite element method for fracture mechanics of rock |
ZHOU Bo, SUN Bo, XUE Shifeng
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(College of Pipeline and Civil Engineering in China University of Petroleum, Qingdao 266580, China)
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Abstract: |
An extended finite element method (XFEM) was used to study the mechanical characteristics and crack propagation behaviors of rock materials, in which the methods for selecting the element displacement mode, the geometric description of plane cracks and the integration of special elements were introduced. The criteria for crack propagation in terms of the maximum hoop stress and an interaction integration method for calculating the stress intensity factor were introduced to formulate the fundamentals of the XFEM model in fracture mechanics of rocks. Then the XFEM model was developed to predict the mechanical behaviors of fractures in rocks, and the model was solved numerically using the MATLAB software. The stress intensity factors of the crack type I and the crack propagation paths of the crack type II were calculated and analyzed using the XFEM model, respectively. The calculation results show that the proposed XFEM method is viable to effectively simulate the crack propagation process and to calculate the fracture mechanics parameters in rock materials. |
Key words: extended finite element method level set method stress intensity factor interaction integral method crack propagation criteria crack propagation path |