High-Order Shape Functions in the Scaled Boundary Finite Element Method Revisited

The scaled boundary finite element method (SBFEM) is a semi-analytical approach to solving partial differential equations, in which a finite element approximation is deployed for the domain’s boundary, while analytical solutions are sought to describe the behavior in the interior of the domain. Since the inception of SBFEM, a number of different shape functions have been applied to interpolate the solution on the boundary. The overarching goal of this communication is to review the respective advantages and disadvantages of the available interpolants in the context of the SBFEM and develop recommendations regarding their application. In addition, we discuss in detail the discretization employed in the so-called diagonal SBFEM.