Enhanced mode II fracture toughness of secondary bonded joints using tailored sacrificial cracks inside the adhesive
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composite science_CSTE108605_edited_202012001961932019.pdf
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Embargo End Date:
2023-01-06
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ArticleAuthors
Wagih, A.Lubineau, Gilles

KAUST Department
Composite and Heterogeneous Material Analysis and Simulation Laboratory (COHMAS)Mechanical Engineering Program
Physical Science and Engineering (PSE) Division
KAUST Grant Number
OSR-2017-CRG6-3388.01Date
2020-12-13Embargo End Date
2023-01-06Submitted Date
2020-07-05Permanent link to this record
http://hdl.handle.net/10754/666858
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The mode II fracture toughness of secondary bonded joints can be improved by creating tailored sacrificial cracks inside the adhesive. To this end, we inserted a PTFE film inside the adhesive bondline during the bonding process to create sacrificial cracks inside the adhesive. We demonstrated the efficiency of this technique through ENF tests that characterize mode II fracture toughness of adhesive-bonded CFRP adherends. We ascribed the improvement in toughness to the reduction of the strain concentration at the crack tip, which delayed the crack propagation and thus improved joint initiation fracture toughness, GIIi, and the maximum load capacity, Pmax. Moreover, after crack propagation, sacrificial cracks arrested the crack propagation at the upper interface, grew secondary backward cracks at the lower interface, and created adhesive ligaments. These three damage mechanisms dissipated more energy during propagation, which improved the propagation fracture toughness, GIIc. The improvement rates depend on the sacrificial crack width and the gap between two successive cracks reaching 96%, 98%, and 25% for GIIi, GIIc and Pmax, respectively, for a 2 mm sacrificial crack width and 5 mm gap. Our approach works well for both thin and thick adhesives and is a simple technique to substantially enhance the toughness of secondary bonded joints.Citation
Wagih, A., & Lubineau, G. (2021). Enhanced mode II fracture toughness of secondary bonded joints using tailored sacrificial cracks inside the adhesive. Composites Science and Technology, 204, 108605. doi:10.1016/j.compscitech.2020.108605Sponsors
This research was funded by King Abdullah University of Science and Technology Office of Sponsored Research (OSR) under award number OSR-2017-CRG6-3388.01.Publisher
Elsevier BVAdditional Links
https://linkinghub.elsevier.com/retrieve/pii/S026635382032399Xae974a485f413a2113503eed53cd6c53
10.1016/j.compscitech.2020.108605