Mode Ii Fatigue Characteristics of a Composite Bonded Joint with Microstructured Adhesive Bondline through Tailored Sacrificial Cracks
Abstract
Previous studies have developed several techniques to enhance the mode II static fracture toughness of adhesive-bonded joints for structural applications. However, in real-world applications, joints are subjected to fatigue loading more frequently than static loading. In a previous study, we demonstrated static mode II toughness improvement of a modified adhesive joint with a microstructured bondline using tailored sacrificial cracks. In this study, we analyzed the mode II fatigue toughness of this joint by employing the end notch flexural test to characterize the mode II fatigue toughness of the modified bonded joints at different loads, i.e., 50%, 60%, and 70% of the maximum static load. The results demonstrated initiation fracture toughness improvement for the joints tested at 70% of maximum static load, and a one-order of magnitude lower crack growth rate than the conventional joint (interfacial crack propagation). The initiation fracture toughness improvement was caused by the presence of the first sacrificial crack, which facilitated the stress redistribution ahead of the crack tip and formed an elongated strain-affected zone. This reduces the stress intensity at the crack tip and, as a result, delays the initiation of the crack. We found that the crack growth rate improvement was associated with the formation of two adhesive ligaments at the sacrificial crack ends, which dissipated large energy due to plastic deformation and ligament breakage.
Recommended Citation
A. Alshedayfat et al., "Mode Ii Fatigue Characteristics of a Composite Bonded Joint with Microstructured Adhesive Bondline through Tailored Sacrificial Cracks," Composites Part A Applied Science and Manufacturing, vol. 180, article no. 108090, Elsevier, May 2024.
The definitive version is available at https://doi.org/10.1016/j.compositesa.2024.108090
Department(s)
Mechanical and Aerospace Engineering
Keywords and Phrases
A. Polymer-matrix composites (PMCs); B. Fatigue; C. Damage mechanics; D. Non-destructive testing; Fracture toughness
International Standard Serial Number (ISSN)
1359-835X
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2025 Elsevier, All rights reserved.
Publication Date
01 May 2024
Comments
King Abdullah University of Science and Technology, Grant BAS/1/1315-01-01