東大数値解析セミナー (UTNAS) 第160回

東京大学大学院数理科学研究科と情報理工学系研究科では,本年度も数値解析セミナーを定期的(月に1,2回程度)に開催致します.
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講演者
Franz Chouly (Universidad de la República)

題目
Finite Element Methods for the Elasto-Plastic Torsion Problem

概要
We will describe finite element methods for the elasto-plastic torsion problem, as a prototype of variational inequality with constraints on the gradient of the solution. This problem has been an object of study from the theoretical viewpoint since the 1970s. From the numerical analysis viewpoint, it remains difficult to obtain optimal a priori error estimates. We will present the numerical analysis and numerical results for three methods based on standard Lagrange finite elements of orden 1 or 2: a direct discretization and a Nitsche discretization of a modified variational inequality, when the source term is constant, and a penalty technique for a non constant source term. Particularly the Nitsche technique yields fully optimal a priori error bounds. This is a joint work with Patrick Hild (Université Paul Sabatier, Toulouse, France) and Tom Gustafsson (Aalto University, Finland).