CAJ | 학술논문

岩石裂纹的扩展是一个经典的不连续问题，常规有限元方法难以实现裂纹扩展过程的仿真模拟。扩展有限元法（XFEM）实现了计算网格与不连续面相互独立，因此模拟移动的不连续面时无需对网格进行重新剖分。本文介绍了 XFEM基本原理和岩石断裂力学常用判据，尝试对岩石类材料单缝Ⅰ型三点弯曲、单缝剪切和双缝平板实验进行模拟。分析结果表明：扩展有限元模拟岩石类材料断裂问题不受网格划分限制，裂纹以实际应力场分布随机扩展；直观地给出岩样的微裂纹产生、演化，直至完全破坏的全过程，并与实验结果吻合。该方法能够应用到岩石断裂力学方面的研究，模拟岩石类材料的宏细观破坏过程，为解决复杂问题提供了方便的途径。
암석렬문적확전시일개경전적불련속문제，상규유한원방법난이실현렬문확전과정적방진모의。확전유한원법（XFEM）실현료계산망격여불련속면상호독립，인차모의이동적불련속면시무수대망격진행중신부분。본문개소료 XFEM기본원리화암석단렬역학상용판거，상시대암석류재료단봉Ⅰ형삼점만곡、단봉전절화쌍봉평판실험진행모의。분석결과표명：확전유한원모의암석류재료단렬문제불수망격화분한제，렬문이실제응력장분포수궤확전；직관지급출암양적미렬문산생、연화，직지완전파배적전과정，병여실험결과문합。해방법능구응용도암석단렬역학방면적연구，모의암석류재료적굉세관파배과정，위해결복잡문제제공료방편적도경。
Rock crack propagation cannot be simulated with conventional finite element method because it is a classic discontinuity problem.Extended finite element method(XFEM)can implement the mutual independence of computational grid and discontinuity.So there is no need to re-mesh the grid model for moving discontinuity simulation.This paper introduces the basic principles of XFEMand universal criterion for rock fracture mechanics. It utilizes XFEMto simulate I mode and II mode fracture in three-point bending test as well as the double-crack shear fracture test.All the obtained results indicate that using XFEMto simulate rock fracture cannot be restrained by mesh generation and the cracks propagate randomly according to the actual stress distribution.The whole process of micro crack generation and evolution until the final total destruction of rock can be directly observed,which have great agreement with laboratory test results.This method has demonstrated its ability to investigate rock fracture mechanics and to simulate rock macroscopic and microscopic fracture process.It provides a convenient way for complex issues solution.