Abstract

Abstract

Abstract

This paper presents a numerical approach based on the finite element method for the estimation of AC interference on buried metallic pipelines sharing the same right-of-way of power transmission lines in presence of mitigation wires. The proposed approach relies on a hybrid technique in order to reduce the mesh size and, in turn, the computational time. The feasibility of the method is demonstrated with application to a standard interference configuration. Some tests were performed in order to assess how the position and material of the mitigation wires affect the induced current on a buried metallic pipeline.

Abstract

This study thoroughly explains the process of implementing Adaptive Mesh Refinement into a Finite Element Analysis program. Using the error norm, a routine for improving an original mesh for an arbitrary 2D structural problem has been developed. By utilizing user-defined relative global error, an optimal mesh for a given level of approximation can be obtained in an iterative manner. The routine (called AMG v1.0) runs with the pre-/postprocessor GiD and the calculation module Calsef, but can easily be tailored to work with other FEA programs. AMG operates with two mesh optimality criteria, which have proven to refine the mesh in a non-oscillatory manner. The open structure, along with the Graphical User Interface, makes AMG suitable for educational and experimental purposes. For validation, six examples within the field of structural engineering have been solved, four of which have been compared favorably with analytical solutions.

The mesh optimality routines used are general, why AMG can be extended to handle more types of elements, 3D analysis, and to be applicable to other types of engineering problems. Above all AMG serves as a first step of implementing Adaptive Mesh Refinement procedures into GiD.

Abstract

The focus of this paper is on the implementation and subsequent improvement of a technique for computing AC interference on buried metallic pipelines due to nearby power transmission lines. In order to perform this task, the finite element method (F.E.M.) is employed. After performing a description of the implementation of the classic F.E.M. approach, a hybrid technique designed to reduce the size of the mesh and therefore the computational time is presented. The results obtained with the two approaches are finally compared.