Enhancement of fracture toughness in secondary bonded CFRP using hybrid thermoplastic/thermoset bondline architecture
KAUST DepartmentComposite and Heterogeneous Material Analysis and Simulation Laboratory (COHMAS)
Mechanical Engineering Program
Physical Science and Engineering (PSE) Division
KAUST Grant NumberCRG2017
Online Publication Date2020-07-29
Print Publication Date2020-10
Embargo End Date2022-08-11
Permanent link to this recordhttp://hdl.handle.net/10754/664613
MetadataShow full item record
AbstractStructures 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 bondline/interface. We specifically designed a wavy net-like thermoplastic insert that was embedded into the thermoset adhesive bondline 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 bondline architecture was carefully tailored to achieve its best performance. We demonstrate that introducing porosities in the adhesive bondline (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).
CitationYudhanto, A., Almulhim, M., Kamal, F., Tao, R., Fatta, L., Alfano, M., & Lubineau, G. (2020). Enhancement of fracture toughness in secondary bonded CFRP using hybrid thermoplastic/thermoset bondline architecture. Composites Science and Technology, 199, 108346. doi:10.1016/j.compscitech.2020.108346
SponsorsThe research funding was supported by Office of Sponsored Research (OSR) of KAUST (King Abdullah University of Science and Technology) under the award number OSR-CRG2017-3388. We also thank COHMAS Laboratory Researchers: Mr. Anh-Quan Vu for assisting preliminary FRT test, Mr. Omar Qahtani for preliminary DCB test and 3D printing and Dr. Ahmed Wagih for Mode II test data.