AN IMPROVED BOUNDARY ELEMENT METHOD FOR THE CHARGE-DENSITY OF A THIN ELECTRIFIED PLATE IN R3

A weakly singular integral equation of the first kind on a plane surface piece Γ is solved approximately via the Galerkin method. The determination of the solution of this integral equation (with the single‐layer potential) is a classical problem in physics, since its solution represents the charge density of a thin, electrified plate Γ loaded with some given potential. Using piecewise constant or piecewise bilinear boundary elements we derive asymptotic estimates for the Galerkin error in the energy norm and analyse the effect of graded meshes. Estimates in lower order Sobolev norms are obtained via the Aubin–Nitsche trick. We describe in detail the numerical implementation of the Galerkin method with both piecewise‐constant and piecewise‐linear boundary elements. Numerical experiments show experimental rates of convergence that confirm our theoretical, asymptotic results. Copyright © 1990 John Wiley & Sons, Ltd