3-D direct current resistivity forward modeling by adaptive multigrid finite element method

Based on the fact that 3-D model discretization by artificial could not always be successfully implemented especially for large-scaled problems when high accuracy and efficiency were required, a new adaptive multigrid finite element method was proposed. In this algorithm, a-posteriori error estimator was employed to generate adaptively refined mesh on a given initial mesh. On these iterative meshes, V-cycle based multigrid method was adopted to fast solve each linear equation with each initial iterative term interpolated from last mesh. With this error estimator, the unknowns were nearly optimally distributed on the final mesh which guaranteed the accuracy. The numerical results show that the multigrid solver is faster and more stable compared with ICCG solver. Meanwhile, the numerical results obtained from the final model discretization approximate the analytical solutions with maximal relative errors less than 1%, which remarkably validates this algorithm.     

重力与磁法在有色金属矿产勘探中的研究进展EI北大核心CSCD

重力与磁法勘探具有致矿异常敏感、勘探成本低、效率高、效果好等优点,在有色金属矿产圈定中发挥了重要作用。随着仪器设备的日益更新、数据处理与解释手段的快速发展,重磁勘探变得越来越成熟,相应的数据处理与反演解释也进入了高维、高精度、高分辨率的阶段。本文从基本原理、仪器设备、方法技术及勘探案例四个方面出发,介绍了重磁勘探法在有色金属矿勘探中的现状与进展,总结归纳了重磁勘探法的发展趋势与应用前景,相关结论可服务于有色金属矿产勘探同行,并为战略性有色金属矿产储量和分布的探明提供一定的支撑。     

基于MPI和OpenMP可控源电磁法三维有限元正演并行模拟

有效提高可控源电磁法三维正演的效率为目前研究的热点。三维CSEM正演各频点计算相互独立,无数据依赖性,具有良好的并行性。单频点的大型稀疏复线性方程组快速生成与求解成为效率的关键。实现了基于MPI的频点间并行计算,提高了多频点计算效率;对于单频点,利用高性能并行多线程直接求解器实现了OpenMP并行求解大型稀疏复线性方程组;最终实现了基于多进程与多线程混合的MPI+OpenMP的多频点可控源三维正演并行计算,大幅度提高三维CSEM有限元正演的效率,最高加速比达到了8.914倍。     

基于阻尼相关系数的锚杆瞬态响应的数学模型

研究锚杆体-锚固介质系统共同作用时弹性波的传播规律,采用与应变相关的阻尼器和与速度相关的阻尼器并行耦合来模拟锚固介质与锚杆体间相互作用,建立锚杆瞬态动测响应的数学模型,讨论其反射特性,通过该模型得出的理论瞬态响应曲线,与实测结果基本吻合,同时发现K1(等效应变阻尼系数)和K2(等效速度阻尼系数)与锚固介质和锚杆体间相互耦合效果相关,K1决定弹性波沿杆体传播能量衰减的速率,K2决定弹性波在杆体某处振动能量的衰减速率。