电阻层析成像有限元仿真模型分析与设计

Analysis and design of finite element models used in electrical resistance tomography

本文根据电阻层析成像(ERT)中常采用的16电极相邻激励模式,以及有限元计算中广泛采用的三角形网格元素划分,比较分析了5种不同拓扑类型模型的对称性误差和结构性误差。仿真结果表明不同类型模型各有优缺点,实际应用中应结合具体情况与系统要求选择理想有限元模型。在此基础上,讨论了网格分布形式、有限元质量等因素对ERT有限元仿真不确定度的影响,并探讨了提高ERT计算精度的有限元网格设计方法。仿真实验表明,传统的按等间隔原理剖分的有限元模型并不合理,而通过适当调整有限元剖分密度等措施可降低ERT有限元计算的不确定度。

The paper analyzes comparative symmetry error and structure error of five different topology meshes on the basis of adjacent injecting method of sixteen-electrode system in ERT and triangular mesh in FEM computation. The simulation results show that there are advantages and disadvantages in different meshes, and the ideal FEM model should be chosen according to practical situation and system requirements. It discusses influences of the FEM simulation uncertainty in ERT from the mesh distributing form and FEM quality. It also discusses the FEM mesh design method to improve ERT computing precision. Simulation experiments make clear that the typical equidistance FEM mesh is not rational and the uncertainty of FEM computing in ERT system can be reduced by suitably adjusting the density of FEM mesh.