Approximation Capabilities of Immersed Finite Element Spaces for Elasticity Interface Problems
Provides theoretical guarantees for immersed finite element methods in elasticity, addressing a known bottleneck in interface problems.
This paper constructs and analyzes immersed finite element spaces for planar elasticity interface problems, proving optimal approximation capabilities regardless of Lamé parameters and interface location.
We construct and analyze a group of immersed finite element (IFE) spaces formed by linear, bilinear and rotated Q1 polynomials for solving planar elasticity equation involving interface. The shape functions in these IFE spaces are constructed through a group of approximate jump conditions such that the unisolvence of the bilinear and rotated Q1 IFE shape functions are always guaranteed regardless of the Lamè parameters and the interface location. The boundedness property and a group of identities of the proposed IFE shape functions are established. A multi-point Taylor expansion is utilized to show the optimal approximation capabilities for the proposed IFE spaces through the Lagrange type interpolation operators.