Contents lists available at ScienceDirect Engineering Failure Analysis journal homepage: www.elsevier.com/locate/engfailanal A multiscale modelling procedure for predicting failure in composite textiles using an enhancement approach N.T. Chowdhury, N.K. Balasubramani, G.M. Pearce ⁎ , C. Tao School of Mechanical and Manufacturing Engineering, The University of New South Wales, Sydney, NSW 2052, Australia ARTICLE INFO Keywords: Multi-scale analysis Hierarchical modelling Dehomogenisation Strain invariant failure theory Onset theory Representative volume elements ABSTRACT Composite materials have largely been analysed for failure and structural performance from the perspective of an anisotropic homogeneous material despite their evident hierarchical nature. Although such an assumption does substantially facilitate the analysis procedure in a computa- tionally efficient manner, predictions on the occurrence of failure differ from reality as the failure mechanisms within composite materials are different from a constituent perspective. This paper demonstrates the ability of a multiscale dehomogenisation procedure that provides failure in- formation at different length scales, namely: the macro- (continuum), meso- (textile) and micro- scale (constituent). This is achieved by adopting an enhancement approach performing simple matrix operations to study the strain distribution. The hierarchical dehomogenisation procedure using Strain Invariant Failure Theory is implemented in Abaqus UMAT subroutine and verified using simple sanity checks and a ‘manual’ sub-modelling technique utilising an open hole tension coupon as an example. A comparison of the two modelling techniques indicate the similar failure predictions at the meso and micro levels with the hierarchical approach presented in this paper being far more computationally efficient. The failure analysis procedure presented in this paper is subsequently demonstrated on a composite I-beam component allowing failure in composite structures to be observed from a constituent perspective where fibre and matrix modes of failure can be identified and examined from an engineering point of view. 1. Introduction Fibre reinforced composite materials are being increasingly used within the aerospace industry due to their high specific me- chanical properties. This sector of the industry has such high demands that it requires composite structures to be pushed to their extreme design limits. When performing engineering failure analysis to design optimised composite structures, different investigation levels are considered as illustrated by the pyramid flowchart in Fig. 1 where there is significant user discretion in determining the amount of attention to be given to each layer of the pyramid. Typically, performing an exhaustive full-scale test might give the most information regarding structural failure behaviour but such tests are expensive to run and are very time consuming. Moving down the pyramid, the tests become more time and cost effective, but the amount of information obtained that is directly relatable to the overall structure becomes clouded with user assumptions and theories. More research is being conducted to rectify some of these assumptions and one of the pivotal methods to achieve this is through devising better computational models to understand the structure-property-performance relationships in these material systems. As a first step in this direction, researchers are implementing multiscale finite element analysis techniques taking microstructural https://doi.org/10.1016/j.engfailanal.2019.04.013 Received 26 November 2018; Accepted 8 April 2019 ⁎ Corresponding author. E-mail addresses: nayeem.chowdhury@unsw.edu.au (N.T. Chowdhury), g.pearce@unsw.edu.au (G.M. Pearce). Engineering Failure Analysis 102 (2019) 148–159 Available online 10 April 2019 1350-6307/ Crown Copyright © 2019 Published by Elsevier Ltd. All rights reserved. T