Modelling mixed-mode rate-dependent delamination in layered structures using geometrically nonlinear beam finite elements

Abstract

Delamination is one of the one most important problems for layered structures, which are widely used in industry (e.g.compositelaminates)andalsooftenpresentinnature(e.g.layeredbiologicaltissue).Inthisworkdelamination is studied using cohesive-zone models (CZMs) where a discontinuous displacement field and a non-linear tractionseparation law on the considered interface are assumed. Authors of the present work have recently shown that beam elements can be used with very good accuracy to model delamination in layered structures both in geometrically linear and non-linear analysis. Beam elements also make use of a smaller number of degrees of freedom, with significant reduction in the overall computational burden. When the fracture process is significantly rate dependent, the traditional fracture-mechanics based approaches can only characterise the phenomenological dependence of the fracture energy on the crack speed. Instead, rate-dependent CZMs, recently developed by the authors, where the different dissipation mechanisms occurring during fracture are separated out, is less phenomenological and better linked to the underlying physics. Combining the highly efficient multi-layer beam model and the novel rate-dependent CZMs is the aim of the project on which the authors of this work are currently collaborating. This work gives a brief overview of authors’ recent work which presents the background for developing a novel multi-layer beam finite element with rate-dependent mixed-mode delamination