A MESH DEFORMATION ALGORITHM FOR FREE-SURFACE PROBLEMS

Employing the simple iterative technique of adjusting the element posi tions using computed potentials to locate the free surface can lead to finite elements with large aspect ratios as the free surface drops to wards the base of the mesh. In particular, free surface modelling of e arth dams with base drains suffer from this problem. The paper suggest s a number of steps which can be taken to alleviate mesh distortion pr oblems and improve the numerical stability of the iterative finite ele ment analysis. This leads to a mesh deformation algorithm which adjust s element widths in a simple fashion depending on the free surface hei ght as the iterations proceed. The algorithm is specialized to the slo ped earth dam problem, but may find application to other geometries. ( C) 1997 by John Wiley & Sons, Ltd.