01324nas a2200121   4500008004100000245008000041210006900121300001300190490000700203520085200210100002601062856011401088       2009                        eng d00aQuasistatic evolution problems for nonhomogeneous elastic plastic materials0 aQuasistatic evolution problems for nonhomogeneous elastic plasti  a89–1190 v163 a<p>The paper studies the quasistatic evolution for elastoplastic materials when the yield surface depends on the position in the reference configuration. The main results are obtained when the yield surface is continuous with respect to the space variable. The case of piecewise constant dependence is also considered. The evolution is studied in the framework of the variational formulation for rate independent problems developed by Mielke. The results are proved by adapting the arguments introduced for a constant yield surface, using some properties of convex valued semicontinuous multifunctions. A strong formulation of the problem is also obtained, which includes a pointwise version of the plastic flow rule. Some examples are considered, which show that strain concentration may occur as a consequence of a nonconstant yield surface.</p>1 aSolombrino, Francesco  uhttps://www.math.sissa.it/publication/quasistatic-evolution-problems-nonhomogeneous-elastic-plastic-materials