PSI - Issue 35

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2019) 000 – 000 il l li t . i ir t. i i tructural Integrity rocedia 00 (2019) 000 – 000

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Procedia Structural Integrity 35 (2022) 210–218

© 2021 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 IWPDF 2021 Chair, Tuncay Yalçinkaya Abstract In- plane shear and mode‒II interlaminar fracture toughness properties o f three-dimensional nanostitch para-aramid/phenolic composites were experimentally studied. Introducing the nanostitching yarn into nanocomposites slightly enhanced their shear strengths and the interlaminar fracture toughness (G IIC ) due to the through-the-thickness reinforcement which was provided by micro filament TOWs and nanotubes. In-plane shear failure mode was predominantly irregular shear hackle marks in the phenolic resin and fibrillar peeling on the fiber due to in-plane shear deformation. However, the failure mode of interlaminar fracture toughness was mainly shear hackles in the interlayer region of the nanostitch composite. Carbon nanotubes in the phenolic resin and filament TOWs probably reduced the stress clustering via friction-debonding-pull-out-sliding as a form of stick-slip. These failure mechanisms probably arrested the crack growth and suppressed delamination in the through-the thickness fiber reinforced zone. As a result, nanostitch aramid composite showed damage tolerance characteristic. 21 he rs. ublish ed by LSEVIER B.V. his is an open access article under the - - license (https://creativecom ons.org/licenses/by-nc-nd/4.0) Peer-revie under responsibility of I P F 2021 Chair, Tun cay alçinkaya Keywords: MWCNTs; aramid fabric; nanostitched reinforcement; in-plane shear; mode-II toughness. MWCNT stitch Para-aramid/Phenolic Nanocomposites i ili i , , l gan 1,2 , N i 3 , l n i 4 , il G 4 1 ano/ icro iber refor esign and o posite aboratory, epart ent of extile ngineering, aculty of ngineering, rciyes University, 38039 Talas-Kayseri, Turkey 2 anotechnology pplication and esearch entre ( ), rciyes niversity, 38039 alas- ayseri, urkey 3 kdag adeni ocational igh School, ozok niversity, 66300 kdag adeni- ozgat, urkey 4 S Industries, 06780, l adag- nkara, urkey str ct In- plane shear and mode‒II interlaminar fracture toughness properties o f three-dimensional nanostitch para-aramid/phenolic c sites ere e eri e tall st ie . I tr ci t e a stitc i ar i t anocomposites slightly enhance t eir s ear stre t s a t e i terla i ar fract re t ess ( IIC ) e t t e t r -t e-t ic ess rei f rce e t ic as r i e icr fila e t s a a t es. I - la e s ear fail re e as re i a tl irre lar s ear ac le ar s i t e e lic resi a fi rillar eeli t e fi er e t i - la e s ear ef r ati . e er, t e fail re e f i terla i ar fract re t ess as ai l s ear ac les i t e i terla er re i f t e a stitc c site. ar a t es i t e e lic resi a fila e t s r a l re ce t e stress cl steri ia fricti - e i - ll- t-sli i as a f r f stic -sli . ese fail re ec a is s r a l arreste t e crac r t a s resse ela i ati i t e t r -t e t ic ess fi er rei f rce z e. s a res lt, a stitc ara i c site s e a a e t lera ce c aracteristic. t . li I . . is s r t li ( ttps://creativeco ons.org/licenses/by-nc-nd/4.0) e - air, s; ara id fabric; nanostitched reinforce ent; in-plane shear; ode-II toughness. 2nd International Workshop on Plasticity, Damage and Fracture of Engineering Materials In-Plane Shear and Interlaminar Fracture Toughness Properties of MWCNT stitch Para-aramid/Phenolic Nanocomposites Kadir Bilisik 1,2* , Gulhan Erdogan 1,2 , Nesrin Sahbaz Karaduman 3 , Erdal Sapanci 4 , Sila Gungor 4 1 Nano/Micro Fiber Preform Design and Composite Laboratory, Department of Textile Engineering, Faculty of Engineering, Erciyes University, 38039 Talas-Kayseri, Turkey 2 Nanotechnology Application and Research Centre (ERNAM), Erciyes University, 38039 Talas-Kayseri, Turkey 3 Akdagmadeni Vocational High School, Bozok University, 66300 Akdagmadeni-Yozgat, Turkey 4 ROKETSAN Industries, 06780, Elmadag-Ankara, Turkey I t r ti l r l ti it , r t r f i ri t ri l ey ords:

* Corresponding author. Tel.: +90352 437 4937/Ext. 32875 or 32851; fax: +90352 437 5784. E-mail address: kbilisik@erciyes.edu.tr * orresponding author. el.: 90352 437 4937/ xt. 32875 or 32851; fax: 90352 437 5784. - ail address: kbilisik erciyes.edu.tr

2452-3216 © 2021 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 IWPDF 2021 Chair, Tuncay Yalçinkaya 2452-3216 2021 he uthors. ublished by I . . his is an open access article under the - - license (https://creativeco ons.org/licenses/by-nc-nd/4.0) eer- revie under responsibility of I 2021 hair, uncay alçinkaya

2452-3216 © 2021 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 IWPDF 2021 Chair, Tuncay Yal ç inkaya 10.1016/j.prostr.2021.12.067