PSI - Issue 28

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2019) 000–000

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 28 (2020) 26–38

1st Virtual European Conference on Fracture A way forward for industry to determine valid cyclic-fatigue relationships for polymer-matrix fibre composites

Rhys Jones a , Anthony J. Kinloch b* a Centre of Expertise for Structural Mechanics, Department of Mechanical and Aerospace Engineering, Monash University, Clayton, Victoria, 3800, Australia. b Department of Mechanical Engineering, Imperial College London, Exhibition Road, London SW7 2AZ, UK. on

Abstract

© 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo In the present paper a novel methodology is proposed for predicting an ‘upper-bound’ (i.e. ‘worst case’) fatigue crack growth (FCG) rate curve from laboratory double-cantilever beam (DCB) test data which is representative of a composite laminate exhibiting no, or only very little, retardation (i.e. slowing) of the FCG rate under fatigue loading, as is the case with most real-life applications. The proposed methodology also takes into account the inherent scatter of such fatigue tests. To achieve this we have employed a variant of the Hartman-Schijve equation. The resulting conservative ‘upper-bound’ FCG rate curve represents a unique and valid ‘upper-bound’ fatigue relationship which may be used in industrial applications for (a) material development, characterisation and comparative studies and (b) design and lifing studies. © 2020 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo Keywords: CFRP; composites; fatigue; fracture mechanics; modelling; service-life; 1. Introduction The growth of delaminations in polymer-matrix continuous-fibre composites under cyclic-fatigue loading in operational aircraft structures has always been a very important factor which has the potential to affect significantly the service-life. __________ * Corresponding author. Tel.:+44-207-594-7082; fax: +44-207-504-7017 E-mail address: a.kinloch@imperial.ac.uk © h u r . s EVIER B.V. r n ht p : ___ __

2452-3216 © 2020 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo

2452-3216 © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo 10.1016/j.prostr.2020.10.005