Journal Home Page Cumulative Index List of all Volumes Complete Contentsof this Volume Previous Article Journal of Convex Analysis 25 (2018), No. 2, 529--543Copyright Heldermann Verlag 2018 Radial Solutions and Free Boundary of the Elastic-Plastic Torsion Problem Sofia Giuffrè D.I.I.E.S., University of Reggio Calabria, Località Feo di Vito, 89122 Reggio Calabria, Italy sofia.giuffre@unirc.it Aldo Pratelli Department Mathematik, University of Erlangen, Cauerstr. 11, 91058 Erlangen, Germany pratelli@math.fau.de Daniele Puglisi Department of Mathematics and Computer Sciences, University of Catania, Viale A. Doria 6, 95125 Catania, Italy dpuglisi@dmi.unict.it [Abstract-pdf] The paper is concerned with radial solutions to the elastic-plastic torsion problem, assuming the free term to belong to $L^p(\Omega)$. In particular, we obtain a necessary and sufficient condition in order that the plastic region exists and we characterize the free boundary. Moreover, we find the explicit radial solution $u \in W^{2,p}(\Omega)$ and the Lagrange multiplier $\overline \mu \in L^p(\Omega)$. Keywords: Elastic-plastic torsion, radial solutions, Lagrange multipliers. MSC: 35B06, 35R35 [ Fulltext-pdf  (117  KB)] for subscribers only.