GGU-SLAB: "Topology" button

This program routine displaces the triangle element nodes so that, where possible, equilateral triangles are created. Equilateral triangles have especially favourable numerical properties. Because the displacement of system boundaries and element boundaries with neighbouring elements consisting of different materials does not make much sense, these element boundaries are fixed from the outset. Nodes with defined displacement boundary conditions also remain unaltered. Optimisation of the FEM mesh can be followed on the screen by setting the "With graphics" check box. The optimisation routine can be aborted at any time by pressing the right mouse button.