A NEW COORDINATE TRANSFORM FOR THE FINITE-ELEMENT SOLUTION OF AXISYMMETRIC PROBLEMS IN MAGNETOSTATICS

Although field computation in two dimensional axial symmetric problems has a longstanding history and its software has acquired the status of robustness and reliability, problems with singularities in the neighborhood of r=O still remain a point of concern. We will demonstrate a simple example which exhibits a disturbing lack of accuracy and seems to mock all ideas of reasonability of finite element solutions. A simple solution to the problem will be presented, consisting of transforming the vector potential into a form which is better adapted to the bilinear interpolation used in first order finite elements. For one dimensional problems with piecewise linear materials this approach yields exact solutions; an increase in accuracy was obtained for other problems also. © 1990, IEEE. All rights reserved.