【作者】 颜伟；

【导师】 谭云亮； 刘传孝；

【作者基本信息】 山东科技大学 ， 工程力学， 2005， 硕士

【摘要】 在工程实践中,由于岩石承受长期荷载作用,变形表现出随时间变化的特征,即蠕变现象,所以许多工程项目处在无休止的变形状态,直至破坏失去稳定。因此,研究蠕变现象,对解决地下工程的设计和维护问题,有十分现实而重要的意义。本文在模拟岩石蠕变变形及破坏方面作了初步尝试,对几种模拟算法进行了比较分析,并作了验证。1)首先根据传统的蠕变模型理论和经典的解决蠕变问题的有限元方法,选择了适于模拟稳定蠕变问题的开尔文模型,采用C++语言编制了软件,模拟单轴压缩条件下岩石试件的变形趋势,与已知试验结论基本一致。2)引入了元胞自动机模型,结合前人的研究成果以及岩石发生蠕变的变形特征,构建了模拟岩石蠕变变形问题的元胞自动机模型,并采用C++语言编制了软件,从能量的角度模拟单轴压缩条件下岩石试件发生衰减蠕变和加速蠕变的变形趋势,与已知试验结论基本吻合。定性分析了均质度对岩石蠕变演化的影响程度。3)对物理元胞自动机(PCA)模型在岩石力学领域的进一步研究做了设想。引入应力、应变和位移等矢量概念,将元胞自动机模型与有限元方法结合起来,建立了差分形式的PCA有限元算法,尝试从矢量的角度模拟岩石的变形及破坏问题。更多还原

【Abstract】 In practical project, the deformation of rock shows the character of changing with time, which is called the creep phenomenon, because of long period of load. So many projects stick into endless deformation and even into failure, and then lose stability. In order to solve the design and maintenance of underground projects, therefore, it is realistic and critical to study the creep phenomenon. In this paper, it is an elementary attempt to simulate the creep deformation and failure of rock, to present two simulated methods, and to make validation. Firstly, According to the finite element method solving the creep problem in a classical way, the Kelvin model is selected, that is suitable to simulate stable creep problem, and the program is written using C++. The software is applied to simulate the deformation trend of test rock under the condition of uniaxial compression, and the conclusions from the simulation are basically consistent with those of creep test. Secondly, the cellular automata theory is introduced in the paper. The achievements of the predecessors and the deformation characters of rock creep are combined in the paper, then the cellular automata model is built used to simulate rock creep. Then the software is written adopting C++, and the deformation trend of test rock is simulated, which is in the state of stable creep and unstable creep, under the condition of uniaxial compression in the sense of energy. The conclusions accord with the known test results. And a qualitative analysis is made. Finally, the new idea is presented about the application of the PCA model in the field of rock mechanics, such concepts as stress, strain and displacement are introduced in the CA model. The CA model and FEM are combined, then the differential PCA-FEM algorithm is set up, which attempts to simulate the deformation and failure of rock in the sense of vector.更多还原