  The scaled boundary finite element method (SBFEM) is capable of generating
polyhedral elements with an arbitrary number of surfaces. This salient feature
significantly alleviates the meshing burden being a bottleneck in the analysis
pipeline in the standard finite element method (FEM). In this paper, we
implement polyhedral elements based on the SBFEM into the commercial finite
element software ABAQUS. To this end, user elements are provided through the
user subroutine UEL. Detailed explanations regarding the data structures and
implementational aspects of the procedures are given. The focus of the current
implementation is on interfacial problems and therefore, element-based surfaces
are created on polyhedral user elements to establish interactions. This is
achieved by an overlay of standard finite elements with negligible stiffness,
provided in the ABAQUS element library, with polyhedral user elements. By means
of several numerical examples, the advantages of polyhedral elements regarding
the treatment of non-matching interfaces and automatic mesh generation are
clearly demonstrated. Thus, the performance of ABAQUS for problems involving
interfaces is augmented based on the availability of polyhedral meshes. Due to
the implementation of polyhedral user elements, ABAQUS can directly handle
complex geometries given in the form of digital images or stereolithography
(STL) files. In order to facilitate the use of the proposed approach, the code
of the UEL is published open-source and can be downloaded from
https://github.com/ShukaiYa/SBFEM-UEL.
