Abstract

Structures made of carbon fiber-reinforced polymer (CFRP) can be assembled using adhesive bonding. However, such bonding is prone to brittle delamination, and a method to improve delamination resistance is desirable. Here, we propose a technique to introduce crack-arrest features that increase the R-curve response by engineering the adhesive bond line/interface. We specifically designed a wavy net-like thermoplastic insert that was embedded into the thermoset adhesive bond line where the new mechanisms of energy dissipation were generated. We demonstrate that the technique is effective at improving mode I fracture toughness of secondary bonded carbon/epoxy by more than 400%. The hybrid thermoset/thermoplastic bond line architecture was carefully tailored to achieve its best performance. We demonstrate that introducing porosities in the adhesive bond line (by adding a limited amount of thermoset adhesive) further improves the fracture toughness. This toughness improvement originates from the extrinsic toughening of the crack-arrest feature, which is enabled by the insert ductility and microstructures (via strand formation, anchoring and stretching).

Department(s)

Mechanical and Aerospace Engineering

Publication Status

Full Text Access

Comments

King Abdullah University of Science and Technology, Grant OSR-CRG2017-3388

Keywords and Phrases

A. Adhesive joints; A. Laminate; B. Delamination; B. Fracture toughness; B. Interface

International Standard Serial Number (ISSN)

0266-3538

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2025 Elsevier, All rights reserved.

Publication Date

20 Oct 2020

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