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) 864–872

© 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 Abstract A modified Shear-lag model and variational approach were used to predict the effect of the crack density on the stiffness degradation for composite laminates with different fiber orientation angle of the cracked layers. Good agreement is obtained by comparing the prediction models and experimental data published by Katerelos. Furthermore the cracked off-axis composite laminate is submitted to hygrothermal conditions. The material properties of the composite are affected by the variation of temperature and moisture, they are based on a micromechanical model of laminates. The transient and non-uniform moisture concentration distribution give rise to the transient elastic moduli of the off-axis cracked composite laminates. The modified shear lag analysis has been extended to study the stiffness properties degradation of high-temperature polymer composite material at both, room temperature and high temperature. The obtained results represent well the dependence of the stiffness degradation on the cracks density, fibre orientation angle of the inner layers and operating temperature. © 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: Transverse cracking; Hygrothermal effect; Off-axis; High temperature 1. Introduction For multidirectional composite laminate, the first damage which appears under uniaxial loads is the matrix cracking in the off axis plies. In the most cases the studies limited to analysis the cross ply lay-up (Berthelot (1997), Vingradov 1st Virtual European Conference on Fracture Effect of high temperature on the stiffness properties of cracked composite laminates with different off-axis angles Mohamed Khodjet Kesba a *, A. Benkhedda a , E.A. Adda bedia b , B. Boukert a a Laboratoire des Sciences Aéronautiques, Institut d’Aéronautique et des études spatiales, Université Blida 1, B.P 270 route de Soumaa, Algerie b Laboratoire de Matériaux et Hydrologie, Université de Sidi Bel Abbès, Algerie

* Corresponding author. Tel.: +213 662788612. E-mail address: mkhojet@hotmail.fr

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.2020.11.055