Simulation: finite elements, boundary elements or hybrids

Paul Boughton

Aconsiderable portion of design engineers routinely use finite elements (FE) calculations for thermalmechanicalelectromagneticacoustic and CFD computations.

For most of these calculations the method has proved to be quite versatile. For certain classes of problems normally found in electromagneticacoustics and thermal radiationthe method has on major drawback.

That isnot only the parts of the problem have to be meshed but the exterior region has to be meshed to some arbitrary distance away as well. This can make the solution of the problem practically impossible especially for 3D problems.

The boundary element (BE) method completely eliminates the problem of having to generate a mesh in the volume of the parts and in the exterior region containing them. In factonly a mesh is required on the surfaces of the parts. The major drawback of this method is dealing with nonlinear materials efficiently.

The ideal situation would then be to have the nonlinear regions modelled with FE and the remainder of the space modelled with BE. Or in other words a hybrid solution where both FE and BE are used in the same problem. This method has been shown to be very effective for certain classes of problems. This hybrid method has been included in some of the advanced simulation packages. 

Integrated Engineering Software is based in WinnipegCanada.


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