ALE ANALYSES OF LOCALIZATION IN WAVE-PROPAGATION PROBLEMS

The computational modelling of localization of deformation in cohesive -frictional materials must be carried out in a proper, accurate and ef ficient manner. A proper solution can be obtained by using an enriched material description such as a non-local damage model or Perzyna's vi scoplasticity model. However, still a large number of finite elements is needed for an accurate description of the localization zone. To imp rove efficiency, mesh adaption is applied here by means of the Arbitra ry Lagrangian-Eulerian (ALE) technique. The ALE technique must typical ly be applied in combination with an enriched material model. Otherwis e, the use of a standard model gives a zero-width solution of the loca lization zone and therefore remeshing results in a continuing decrease of finite element size. Implementation of this method requires the ad dition of convective forces in the equations of motion, transport of t he state variables and the formulation of a remeshing strategy. The re meshing strategy heavily determines the success of the ALE method. Thr ee examples of wave propagation have been treated and it is shown that a suitable remeshing strategy in combination with an enriched materia l model leads to proper, accurate and efficient analyses of the locali zation process. (C) 1998 John Wiley & Sons. Ltd.