Writing a FEM code is not terribly difficult, especially if one develops the code UTILIZING a general set of subroutines, e.g., input data, integration, assembly, boundary conditions,output, etc. About 90% of a FEM PROGRAM is generic, which is fairly common among most FEM codes – they TEND to use similar matrix solvers, quadrature rules, and matrix assembly procedures; I/O is usually the major difference among commercial FEM codes – some are easy, and some are not so easy to learn and use. A source listing of the FORTRAN codes can be found in the FORTRAN file folder; FLOW charts can be obtained from the authors. Likewise, MATLAB and MathCad files are also available. One of the best commercial packages now on the market is COMSOL, which also allows users to write their own solver packages and PDEs.

Writing a FEM code is not terribly difficult, especially if one develops the code utilizing a general set of subroutines, e.g., input data, integration, assembly, boundary conditions,output, etc. About 90% of a FEM program is generic, which is fairly common among most FEM codes – they tend to use similar matrix solvers, quadrature rules, and matrix assembly procedures; I/O is usually the major difference among commercial FEM codes – some are easy, and some are not so easy to learn and use. A source listing of the FORTRAN codes can be found in the FORTRAN file folder; flow charts can be obtained from the authors. Likewise, MATLAB and MathCad files are also available. One of the best commercial packages now on the market is COMSOL, which also allows users to write their own solver packages and PDEs.