A consistent interface element formulation for geometrical and material nonlinearities

TL;DR

This paper introduces a new, consistent interface element formulation for large deformation analyses that accurately captures coupled material and geometrical nonlinearities, applicable to various interface behaviors.

Contribution

It provides a unified derivation of an interface element that accommodates any kinematic interpolation and constitutive model, implemented in popular finite element software.

Findings

The new interface element is mesh independent.

It demonstrates robustness across different nonlinear models.

Experimental comparison confirms predictive accuracy.

Abstract

Decohesion undergoing large displacements takes place in a wide range of applications. In these problems, interface element formulations for large displacements should be used to accurately deal with coupled material and geometrical nonlinearities. The present work proposes a consistent derivation of a new interface element for large deformation analyses. The resulting compact derivation leads to a operational formulation that enables the accommodation of any order of kinematic interpolation and constitutive behavior of the interface. The derived interface element has been implemented into the finite element codes FEAP and ABAQUS by means of user-defined routines. The interplay between geometrical and material nonlinearities is investigated by considering two different constitutive models for the interface (tension cut-off and polynomial cohesive zone models) and small or finite deformation for the continuum. Numerical examples are proposed to assess the mesh independency of the new interface element and to demonstrate the robustness of the formulation. A comparison with experimental results for peeling confirms the predictive capabilities of the formulation.