Estimation of interfacial toughness using bilayer fiber bundle compact tension (BFBCT) specimens

• Published in: Composites science and technology Vol. 161; pp. 1 - 7
• Main Authors: Qi, Guocheng, Zhang, Boming, Du, Shanyi
• Format: Journal Article
• Language: English
• Published: Barking Elsevier Ltd 16.06.2018; Elsevier BV
• Subjects: Aramid fiber reinforced plastics; Bonding strength; Bundling; Carbon; Carbon fiber reinforced plastics; Carbon-epoxy composites; Compact tension; Crack propagation; Delamination; Estimating techniques; Fiber/matrix bond; Fibers; Fracture toughness; Interface; Interfacial strength; Interlayers; Matrix; Polymer-matrix composites (PMCs); Propagation modes; Fiber/matrix bond; Polymer-matrix composites (PMCs); Interface; Fracture toughness
• ISSN: 0266-3538; 1879-1050
• DOI: 10.1016/j.compscitech.2018.03.029

This work aims at characterizing the interfacial toughness based on the mode I interlayer fracture toughness of bilayer fiber bundle compact tension (BFBCT) specimens. Extensive fiber/matrix interfacial deboning was found along the crack propagation path in mode I delamination test of BFBCT specimens. The apparent GIc values could distinguish interfacial toughness properties of different carbon and aramid fiber/matrix systems. The transverse fiber bundle tension (TFBT) test for evaluating interfacial bonding strength was also performed as a comparison. It was found that the interface between T800H carbon fiber and epoxy was both the strongest and the toughest among all tested carbon fiber/epoxy interfaces. Compared with carbon fibers, aramid fibers possessed a higher interfacial toughness but a lower interfacial strength. The mode I delamination test of BFBCT specimens is a simple and reliable method for evaluating interfacial toughness in composites. BFBCT test as well as TFBT test can be used to comprehensively characterize the strength and toughness properties for fiber/matrix interface based on fiber bundle specimens.