Im Rahmen der Seminarreihe des SFB 528 spricht am 21.6.2010 Prof. Dr. Jerzy Pamin vom Institut for Computational Civil Engineering der Cracow University of Technology über „Numerical models of localized deformations“. Die Veranstaltung beginnt um 13.30 Uhr im Raum C204, Willers-Bau (Zellescher Weg 12/14). Wie üblich, hier der englischsprachige Abstract:
The lecture is a short overview of problems related to the numerical analysis of localized deformations. Attention is focused on quasi-brittle and frictional materials. After defining the localization phenomenon and providing its theoretical interpretation, the problem of pathological mesh sensitivity of finite element simulations is illustrated.
Two selected gradient-enhanced plasticity and damage models are presented as possible solutions of the problem of well-posedness loss of the (I)BVP, caused by material instability. In the gradient plasticity formulation a Laplacian-dependent yield condition is used and in the gradient damage theory an additional averaging equation for an equivalent strain measure is employed. Finite element formulations of both models are derived.
Selected applications of the models in the numerical simulation of strain localization are then presented. A one-dimensional tensile bar benchmark and a reinforced concrete beam in four-point bending are used to confront the features of the models. Moreover, a slope stability test is simulated using gradient plasticity and a Brazilian split test is computed using gradient damage. The discussion of wave dispersion and localization in dynamics completes the lecture.