Asymptotic boundary conditions for axisymmetric finite element electrostatic analysis

Asymptotic boundary conditions (ABC) for rectangular outer boundaries are formulated and used for the finite element computation of axisymmetric electrostatic fields. ABC-s for rectangular boundaries are more efficient than ABC-s with circular boundaries for problems with large aspect ratios. To illustrate this formulation, three axisymmetric electrostatic problems are solved. Potential distributions and electric field strengths are obtained. The results using ABC-s are compared with analytic solutions or solutions obtained by boundary truncation techniques