PSI - Issue 45

ScienceDirect Structural Integrity Procedia 00 (2022) 000 – 000 Structural Integrity Procedia 00 (2022) 000 – 000 Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Available online at www.sciencedirect.com ScienceDirect

www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia

Procedia Structural Integrity 45 (2023) 117–124

© 2023 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 Prof. Andrei Kotousov Abstract Short glass fiber-reinforced thermoplastics (SGFRTPs) are being used to reduce carbon dioxide emissions from transportation equipment, especially domestic vehicles, because of their properties and because they are lighter than metal or ceramic materials. Interfacial shear strength (IFSS) strongly affects mechanical properties of SGFRTPs, such as the impact strength. In recent years, investigations of IFSS and impact strength have been very active. Positive correlation between these properties is often reported, but no clearly defined quantitative relation has been found. This study used the short beam method and the notched Charpy impact test to elucidate IFSS and the impact strength of injection-molded SGFRTPs with varying fiber contents: IFSS decreases concomitantly with increasing fiber content; the notched Charpy impact strength increases concomitantly with increasing fiber content. Fiber pull-out occurred along the entire fracture surface. Findings confirmed that fiber pull-out occurred with both crack initiation and propagation, indicating that energy absorption in the impact test was entirely attributable to the frictional energy necessary for fiber extraction. Based on this conclusion, a mechanical model was developed to explain the notched Charpy impact strength of SGFRTP injection molded products in terms of their IFSS, pull-out fiber length, and fiber orientation angle. The impact strength calculated using the predicted results shows good agreement with the experimentally obtained results. © 2023 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 Prof. Andrei Kotousov Keywords: Fiber-reinforced thermoplastics; injection molding; interfacial shear strength; notched Charpy impact strength; short beam method. 1. Introduction Reduction of greenhouse gases such as carbon dioxide is recognized today as a common issue to be addressed worldwide to ameliorate global warming. Reducing carbon dioxide emissions from vehicles such as automobiles and aircraft is particularly necessary. Short glass fiber-reinforced thermoplastics (SGFRTPs) are being used to reduce carbon dioxide emissions from transportation equipment, especially domestic vehicles, because they are lighter than 2452-3216 © 2023 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 Prof. Andrei Kotousov Relationship between interfacial shear strength and impact strength of injection molded short glass fiber-reinforced thermoplastics Quan Jiang a , Tetsuo Takayama a, *, Akihiro Nishioka a a Graduate School of Organic Materials Science, Yamagata University, 4-3-16, Jonan, Yonezawa, Yamagata, Japan Abstract Short glass fiber-reinforced thermoplastics (SGFRTPs) are being used to reduce carbon dioxide emissions from transportation equipment, especially domestic vehicles, because of their properties and because they are lighter than metal or ceramic materials. Interfacial shear strength (IFSS) strongly affects mechanical properties of SGFRTPs, such as the impact strength. In recent years, investigations of IFSS and impact strength have been very active. Positive correlation between these properties is often reported, but no clearly defined quantitative relation has been found. This study used the short beam method and the notched Charpy impact test to elucidate IFSS and the impact strength of injection-molded SGFRTPs with varying fiber contents: IFSS decreases concomitantly with increasing fiber content; the notched Charpy impact strength increases concomitantly with increasing fiber content. Fiber pull-out occurred along the entire fracture surface. Findings confirmed that fiber pull-out occurred with both crack initiation and propagation, indicating that energy absorption in the impact test was entirely attributable to the frictional energy necessary for fiber extraction. Based on this conclusion, a mechanical model was developed to explain the notched Charpy impact strength of SGFRTP injection molded products in terms of their IFSS, pull-out fiber length, and fiber orientation angle. The impact strength calculated using the predicted results shows good agreement with the experimentally obtained results. © 2023 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 Prof. Andrei Kotousov Keywords: Fiber-reinforced thermoplastics; injection molding; interfacial shear strength; notched Charpy impact strength; short beam method. 1. Introduction Reduction of greenhouse gases such as carbon dioxide is recognized today as a common issue to be addressed worldwide to ameliorate global warming. Reducing carbon dioxide emissions from vehicles such as automobiles and aircraft is particularly necessary. Short glass fiber-reinforced thermoplastics (SGFRTPs) are being used to reduce carbon dioxide emissions from transportation equipment, especially domestic vehicles, because they are lighter than 2452-3216 © 2023 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 Prof. Andrei Kotousov 17th Asia-Pacific Conference on Fracture and Strength and the 13th Conference on Structural Integrity and Failure (APCFS 2022 & SIF 2022) Relationship between interfacial shear strength and impact strength of injection molded short glass fiber-reinforced thermoplastics Quan Jiang a , Tetsuo Takayama a, *, Akihiro Nishioka a a Graduate School of Organic Materials Science, Yamagata University, 4-3-16, Jonan, Yonezawa, Yamagata, Japan 17th Asia-Pacific Conference on Fracture and Strength and the 13th Conference on Structural Integrity and Failure (APCFS 2022 & SIF 2022)

2452-3216 © 2023 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 Prof. Andrei Kotousov 10.1016/j.prostr.2023.05.004