// Construct finite element load.
        // fem - finite element model
        public FeLoad(FeModel fem)
        {
            FeLoad.fem = fem;
            RD         = FeModel.RD;

            spLoad = new double[fem.nEq];
            dpLoad = new double[fem.nEq];
            dhLoad = new double[fem.nEq];
            sDispl = new double[fem.nEq];
            dDispl = new double[fem.nEq];
            RHS    = new double[fem.nEq];

            if (fem.thermalLoading)
            {
                dtemp = new double[fem.nNod];
            }
            sg = new SurfaceGeometry(fem);
        }
 // Constructor for stress increment.
 // fem - finite element model
 public FeStress(FeModel fem)
 {
     this.fem = fem;
 }