3Delectrostatic simulation software helps in the design and analysis of electronic equipment and components, including striplines, high-voltage insulators, MEMS, bushings, and shielding. Now Integrated Engineering Software of Winnipeg, Canada has developed a multi-physics material editor to allow integrated magnetic, electrical, thermal and mechanical property definitions. Called Coulomb, the software uses Boundary Element Method (BEM) techniques. (BEM in turn uses Maxwell’s equations solved in integral form, which utilize Green’s function relating the source to the voltage or electric field at any point.) Since only elements on surfaces are required, components can be moved or rotated relative to each other without having to generate a new 3D mesh between them. This ability to handle arbitrarily shaped barriers is BEM’s main advantage. On the other hand, FEM — another dominant numerical technique in computeraided engineering — requires entire designs (including surroundings) to be modeled with finite elements: volume mesh. A system of generated linear equations returns the potential (scalar or vector) at the nodes of each element.

Another benefit to BEM: Since only elements on interfaces are involved in solution procedures, problem modifications are easy. Results are more precise because the integration operation is smoother than FEM’s differentiation operation. This can be readily seen when comparing the field plots of both methods.

With BEM the analysis of unbounded structures (the electromagnetic fields around an electric motor, for example) are solved without additional computations, because exterior fields are calculated just as interior fields are. The field at any point in space can be calculated — even at infinity.

BEM drawbacks include the fact that modeling nonlinear phenomena requires a volume mesh, diminishing the technique’s benefit; in fact, for a saturating nonlinear magnetic problem, the saturation characteristic is better solved with FEM.

*Integrated Engineering Software> (204)632-5636.*