基于高性能并行计算的隧道开挖数值模拟

随着岩土工程规模的不断扩大、复杂性的增加以及计算参数的多样化和计算精度的提高, 人们对于计算机计算能力的要求越来越高, 然而单处理器无法满足这类大规模计算.从数据输入、区域分解、线性方程组的迭代求解、后处理等方面详细阐述高性能计算平台上并行有限元求解大规模岩土工程的关键问题.提出了利用MPI2的新特性进行海量数据的分段并行读入, 采用ParMetis软件并行地进行区域分解, 实现了前处理过程的完全并行化; 采用基于Jacobi预处理技术的预处理共轭梯度法(PCG)进行线性方程组的并行迭代求解; 采用Paraview软件实现了后处理的并行可视化.在深腾7000系统上对某隧道工程的三维开挖过程进行了数值模拟, 对其并行性能进行了分析和评价, 验证了采用的区域分解算法和系统方程组的求解方法的可行性, 并且具有较高的加速比和并行效率. 

Analysis of Numerical Simulation of Tunnel Excavation Based on High Performance Parallel Finite Element Computing

With the expansion of the scale of geotechnical engineering, the increase of the complexity and diversity of the calculation parameters and the improvement of calculation accuracy, the requirement of computer computing power is higher, but a single processor can't meet this kind of large-scale computing.Key issues involving the data input, domain decomposition technique, iteration solution algorithm of linear system, and post processing for large scale geotechnical engineering using parallel finite element method based on high performance computation platform are presented in this paper. The study includes a case analysis of a tunnel evacuation in the following procedure. A new feature was employed so that massive data can be read in parallel, and parallel software, i.e. ParMetis was used to decompose the domain, then the pre-process was in completely parallel. The preconditioned conjugate gradient method based on Jacobi preconditioner was applied to solve linear system. In post processing, the parallel visual model was obtained through the Paraview software. A 3D tunnel excavation was simulated in DeepComp 7000 system, on basis of which the parallel performance is analyzed and evaluated, Verified by domain decomposition algorithm and the feasibility of the method of solving the system equations, and has high speedup ratio and parallel efficiency.