【作者】 张永彬；

【导师】 唐春安；

【作者基本信息】 东北大学 ， 采矿工程， 2007， 博士

【摘要】 随着我国大型、超大型岩土工程的建设,岩石材料脆性破坏与工程结构灾害的研究面临着严重的挑战。岩石工程结构尺度巨大,涉及大量多相细观结构、宏观结构和界面,岩石工程中岩体结构失稳和破裂过程数值分析必须采用巨大的单元数目,需要巨大的计算容量和计算速度,而且岩石工程中的破裂问题数值模拟是一个从变形起始到最终破坏的漫长过程,这个过程对数值模拟而言周期非常长,需要极高的计算速度,对计算能力提出了较高的要求,而传统的单机串行分析方法无法满足工程需要,因而需要发展基于并行计算技术的大规模岩石结构破坏过程数值分析软件系统,以满足岩石力学和工程发展的需求,深入分析岩石材料细观破坏本质、进行工程稳定性评价。本论文在课题组原有工作基础之上,围绕岩石破裂过程并行分析这一主题,开展了以下几个方面的工作：1.完成了基于Jacobi预处理稳定双共轭梯度法的分布式集群环境下的并行求解器。并行求解器能够充分利用计算和通信的重叠以达到降低通信延迟的目的,其对存储要求较低,计算速度较快,能够完成大规模线性方程组的求解。2.讨论了有限元区域分解实施过程中有限元的网格无重叠划分、数据分割以及信息管理实现细节,构建了有限元计算子区域的有限元信息以及数据的局部化存储,并同时构建了并行计算的通信环境。3.基于有限元区域分解方法和并行Jacobi预处理稳定双共轭梯度法,采用MPICH和Fortran编制了三维弹性有限元并行计算程序。算例表明并行计算程序具有较高的性能和良好的可扩展性。4.设计了基于客户机-服务器模型的分布式岩石破裂过程分析并行分析系统(RFPA3D-Parallel),采用WindowsXP PC机作为客户机,并行计算机作为服务器提供计算资源。通过面向连接协议的socket服务实现了客户机-服务器模型,完成了跨平台系统的信息通讯和数据传递功能,使得WindowsXP和Linux能够协调处理,从而实现了面向网络的岩石破裂过程并行分析系统。目前在所使用的32计算结点集群环境下,并行计算程序使用12个计算结点24个CPU就可以完成300万六面体单元近千万自由度的岩石破裂过程分析。5.通过应用RFPA3D-Parallel数值分析系统实现了不同主应力水平下三层层状岩石结构模型中等间距裂纹数值模拟。一共进行了直接拉伸、双向不等应力拉伸和双向等应力拉伸三种不同类型9种不同主应力比条件下的裂纹等间距数值模拟。数值模拟再现了裂纹的萌生、扩展以及贯通,最终形成不同模式的裂纹的整个形成过程。9种不同主应力比条件下的裂纹等间距数值模拟结果表明随主应力水平不同,裂纹模式由平行裂纹模式转变为多边形裂纹模式。从而表明RFPA3D-Parallel数值分析系统在岩石工程结构破坏分析领域具有广泛潜在的应用前景,它为岩石工程结构破裂过程分析提供了一个强有力的数值分析工具。更多还原

【Abstract】 With large and superlarge rock engineering development, numerical analysis of rock mass structure instability and failure process highly demands powerful computation ability, while serial numerial method can not satisfy engineering and science research demands.So large scale rock structure failure process numerical analysis system based on parallel computation technique need to be developed to fulfill the demand of rock mechanics and engineering and to study the micro-failure mechanism of rock material and assess engineering stability. On the basis of our group work, focusing on the theme, this thesis has done the following work mainly:1.The parallel solver of Jacobi preconditioned Biconjugate Gradient Stabilized method (J-BICGSTAB) is implemented in the distributed memery environment. The solver makes use of the communication and computation overlapping in order to reduce the latency of the communication. The solver with low memory requirement and high calculating speed is able to solute the large scale linear equation system.2.The implementations of nonoverlapping grid partition,data partition and information management in fininte element domain decomposition are discussed. Through domain decomposition,fininte element information of subdomains and communication environment of parallel computation are constructed.The stored data of submeshes are localized.3.On the basis of the JBICGSTAB method and domain decomposition method, three-dimensional linear elastic finite element program is coded using MPICH and Fortran90 language. Numerical tests indicated that the code has high performance and good scalability.4.Distributed rock failure process parallel analysis system based on client-server model (RFPA3D-Parallel) is proposed.The PC installed Windows XP serves as client and a cluster whose os is Linux serves server offering computating resource.The client-server model is finished by connection-oriented protocol socket service.So the Windows system and Linux system is able to work together and rock failure process parallel analysis system is implemented.At present, the parallel program can be used to fulfill rock failure process analysis of models with more than ten million degrees of freedom with 24 CPUs on a 32-node cluster.5.Numerial simulation of fracture spacing in three-layered rock materials models with different principal stress ratios is done with RFPA3D-Parallel.Three types of numerical tests are performed:directional stretch, anisotropic stretch and isotropic stretch. The modeling results reproduce the complete processes from the crack initiation and propagation to coalescence forming different fracture pattern. The numerical simulation results of nine principle stress ratios show pattern transition from parallel to polygonal fratures.The modeling results indicate that RFPA3D-Parallel is a powerful numerical tool to analyze large scale rock failure process and has abroad and potential application prospects.更多还原