A locking-free discontinuous Galerkin method for linear elasticity in locally nearly incompressible heterogeneous media

• Published in: Applied numerical mathematics Vol. 63; pp. 105 - 116
• Main Authors: Di Pietro, Daniele A., Nicaise, Serge
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.2013; Elsevier
• Subjects: Composite materials; Convergence; Design engineering; Discontinuous Galerkin method; Divergence; Elasticity; Estimates; Galerkin methods; Linear elasticity; Locking-free method; Mathematical models; Mathematics; Numerical Analysis; Tuning; Discontinuous Galerkin method; Composite materials; Linear elasticity; Locking-free method; locking-free method; linear elasticity; discontinuous Galerkin method; composite materials
• ISSN: 0168-9274; 1873-5460
• DOI: 10.1016/j.apnum.2012.09.009

In this work we consider the problem of numerical locking in composite materials featuring quasi-incompressible and compressible sections. More specifically, we start by extending a classical regularity estimate for the H1-norm of the divergence of the displacement field to the heterogeneous case. The proof is based on a reformulation of the elasticity problem as a Stokes system with nonzero divergence constraint. This result is then used to design a locking-free discontinuous Galerkin method. The key point is to make sure that the multiplicative constant in the estimate of the convergence rate uniquely depends on this bounded quantity. Thanks to a fine tuning of the penalty term, the lower bound for the penalty parameter appearing in the method is simply expressed in terms of the space dimension. To conclude, numerical validation of the theoretical results is provided.