PSI - Issue 21

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

www.elsevier.com/locate/procedia

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Procedia Structural Integrity 21 (2019) 146–153 1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials Fracture Toughness (Mode-II) of Nanostitched Composites Kadir Bilisik 1, ⃰ Gulhan Erdogan 1 Erdal Sapanci 2 and Sila Gungor 2 1 Nano/Micro Fiber Preform Design and Composite Laboratory, Department of Textile Engineering, Faculty of Engineering, Erciyes University, 38039 Talas-Kayseri, Turkey 2 ROKETSAN Industries, 06780, Elmadag-Ankara, Turkey Abstract The properties of fracture toughness (mode-II) of nanostitched carbon/epoxy composites were investigated. The mode-II of the nanostitched structure demonstrated extraordinary enhancement considering to the control sample. It was proved that carbon nanostitching yarn in the though-the-thickness of the preform structure was adequate. The fundamental mechanism for raising the mode-II strength in the nanostitched composite was the interlayer matrix breakages predominantly as a form of shear hackle marks in where nanostitching suppressed the layer to layer opening in stitching region during crack growth. Multiwall carbon nanotubes in the matrix and filament also diminished the stress clustering perhaps as a form of friction, filaments/matrix debonding in the interlaced unit cell and filament slippage in the failed matrix zone. So, nanostitched carbon/epoxy composite showed better interlainar shear properties. 1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials Fracture Toughness (Mode-II) of Nanostitched Composites Kadir Bilisik 1, ⃰ Gulhan Erdogan 1 Erdal Sapanci 2 and Sila Gungor 2 1 Nano/Micro Fiber Preform Design and Composite Laboratory, Department of Textile Engineering, Faculty of Engineering, Erciyes University, 38039 Talas-Kayseri, Turkey 2 ROKETSAN Industries, 06780, Elmadag-Ankara, Turkey Abstract The properti s of fracture toughness (mode-II) of nanostitched carbon/epoxy composites were investi ated. The mode-II of the stitched s ructure demonstrated extraordinary enhancement considering to the control sample. It was proved that carbon nan stitching yarn in the tho gh-the-thickness of he reform structure was dequate. The fundamental mecha ism for raising th m de-II strength in the nanostitched composite was the interlayer matrix breakages predominantly as a form of shear hackle marks in where nanostitching suppressed the layer to layer opening in stitching region during crack growth. Multiwall carbon nanotubes in the matrix and filament also diminished the stress clustering perhaps as a form of friction, filaments/matrix debonding in the interlaced unit cell and filament slippage in the failed matrix zone. So, nanostitched carbon/epoxy composite showed better interlainar shear properties. © 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the 1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials organizers © 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/ Peer-review under responsibility of the 1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials organizers © 2019 The Authors. Published by Elsevier B.V. This is an open access article und r the CC BY-NC-ND license ( ttp://cr tivecommons.org/licenses/by-nc-nd/4.0/ Peer-review under responsibility of the 1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials organizers Keywords: Carbon nanotubes; nanoprepreg; nanostitching; mode‒II toughness; shear hackle.

Keywords: Carbon nanotubes; nanoprepreg; nanostitching; mode‒II toughness; shear hackle.

⃰ Corresponding author. Tel.: +90352 207 66 66/Ext. 32875 or 32851; fax: +90352 437 5784. E-mail address: kadirbilisik@gmail.com

2452-3216 © 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/ Peer-review under responsibility of the 1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials organizers 2452-3216 © 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/ Peer-review under responsibility of the 1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials organizers ⃰ Corresponding author. Tel.: +90352 207 66 66/Ext. 32875 or 32851; fax: +90352 437 5784. E-mail address: kadirbilisik@gmail.com

2452-3216 © 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the 1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials organizers 10.1016/j.prostr.2019.12.096