GGU-SLAB: Bandwidth optimisation/equation solver selection

After pointing to the "System/Analyse" or, alternatively, pressing [F5], the equation system bandwidth is examined, and a message box displayed where necessary. If you do not agree with the bandwidth optimisation the analysis is cancelled.

NOTE ON BANDWIDTH:
Finite-element methods give rise to equation systems which, depending on the system, only have values different to "0" in the region of the principal diagonals. The iterative equation solver contained in the FEM applications uses this to save memory and thus shorten computation time. The maximum distance between the principal diagonal and the system’s non-zero element most distant from the principal diagonal is known as the bandwidth. In principle, iterative equation solvers do not require bandwidth optimisation. However, the results are much more stable and the computation time shorter if the bandwidth is small.

Following the bandwidth optimisation, a dialog box opens where "Cholesky" or "Iterative" can be selected as equation solver. Information on the differences between the two equation solvers can be read by pressing the "Equation solver info" button. If you start the analysis by clicking "OK" different dialog boxes open depending on the selected analysis method (subgrade reaction modulus or constrained modulus).