Panagiostis Dimakis M.Sc, Ph.D

Agree with Pete. Its problem dependent and you really need to check out your grid. My experience is that quadrilateral elements work better, so if you have a choice ... The size of the elements in the Z-dir is also important. You might have to insert several numerical layers to get stability. I don't usually employ user stepping. As Pete says you need to check the results all the time for errors. Prefer to reduce the error tolerance to 10[sup]-4[/sup] or 10[sup]-5[/sup]  ( using FE/BE) much slower but more stable. A 30 year simulation with e.t.10[sup]-4[/sup] took 2 days with some oscillations but nevertheless... With e.t 10[sup]-5[/sup] no visible oscillations but took almost 4 days. I suppose that managing the errors is part of the "fun" of modeling.

cheers
Panos

Hi Chris

Its fairly easy to calculate the area of an triangular element from the nodal coordinates. I can give you the equation if you need it.