Abstract
This paper proposes a new formulation to impose Dirichlet boundary conditions on immersed boundary Cartesian Finite Element meshes. The method uses a recovered stress field calculated by Superconvergent Patch Recovery to stabilize the Lagrange multiplier formulation of the problem. The optimal convergence of the method and the convergence of the proposed iterative procedure are demonstrated. The proposed method is also suitable for problems with non-linear material behavior. Some numerical examples are included to confirm the theoretical results.