19.5.3. Stabilization Energy

Stabilization can help with convergence problems, but it can also affect accuracy if the stabilization energy or forces are too large. Although Ansys automatically reports the stabilization force norms and compares them to internal force norms, it is still very important to check the stabilization energy and forces to determine whether or not they are excessive. If the stabilization energy is much less than the potential energy (for example, within a 1.0 percent tolerance), the result should be acceptable. Stabilization energy is not available to the Samcef or ABAQUS solver.

When stabilization energy is large, check the stabilization forces at each DOF for all substeps. If the stabilization forces are much smaller than the applied loads and reaction forces (for example, within a 0.5 percent tolerance), the results are still acceptable. Such a case could occur when an elastic system is loaded first, then unloaded significantly. It is possible that the final element potential energy is small and stabilization energy is relatively large, but all stabilization forces are small. Currently, stabilization forces are accessible in the .OUT file.

Even when both stabilization energy and forces are too large, the results could still be valid. Such a scenario is possible when a large part of an elastic structure undergoes large rigid body motion (as in a snap-through simulation). In such a case, the stabilization energy could be large as well as the stabilization force for some DOFs at some substeps, but the results could still be acceptably accurate. Nevertheless, consider the results along with other support data and use your own discretion.

To insert a Stabilization Energy result, highlight the Solution object in the tree, then select Stabilization Energy from the Solution Context Tab or right-click the object and choose Insert> Energy> Stabilization Energy.

The following figure shows an example stabilization energy contour plot: