A critical assessment of the fragmentation test for glass/epoxy systems

Deformation micromechanics of model glass fibre composites

“…Feillard and co-workers [28] found values of 65 and 70 MPa for two different phenolic resin systems by simulation methods. They also found that debonding did not occur, and this was thought to be due to the presence of coalescing ''penny-shaped cracks'' [28]. Shear stresses of the order of about 80 MPa were recorded for a glass fibre/epoxy system by Shioya and Takaku [29].…”

“…There are a number of other independently reported values of the maximum ISS for glass-epoxy composites, determined by the Kelly-Tyson approach [2]. Feillard and co-workers [28] found values of 65 and 70 MPa for two different phenolic resin systems by simulation methods. They also found that debonding did not occur, and this was thought to be due to the presence of coalescing ''penny-shaped cracks'' [28].…”

Fibre/resin interaction in fragmentation tests: coaxial vs. simple specimens comparison

“…As discussed in the Introduction, the fibre fracture mainly occurs in the nonlinear part of the stress-strain curve of the LY556 and stress-strain curves become very flat at 100 and 120 ЊC. As pointed out by Feillard et al (1993), the actual stresses in the resin close to the fibre surface are not uniform and cannot be compared directly with the macroscopic properties illustrated by the stress-strain curve.…”

“…3), saturation is obtained for Ϸ 4% strain, but to make sure that the fracture has been fully completed, the ultimate strain of the resin has to exceed 4%, making the final plateau quite visible. As reported elsewhere (Feillard et al, 1993), saturation is achieved with carbon fibres only because the fibre/resin debonding that limits the elastic stress transfer is a major feature of the interfacial scenario; with glass fibres saturation is usually not achieved for a number of reasons.…”

Analysis of hygrothermally induced fiber fracture in single fiber composite using fiber Bragg grating

“…Many efforts have been devoted in the past in understanding the stress transfer between fiber and matrix and the adhesion energy of the components in order to improve the mechanical performance of the composite itself. With this aim numerous experimental techniques in particular, fiber fragmentation [1], fiber pull out and microdebonding tests, as well as theoretical approaches including shear lag analysis [2] and its successive modifications have been developed. However, the relevant parameters determined using such experimental techniques are strongly dependent on fiber sizing, residual stresses present in the composite as well as hygro-thermal ageing to which the structure can be subjected during service life.…”