Investigation of load transfer between the fiber and the matrix in pull-out tests with fibers having different diameters

The effect of carbon nanotubes on the fracture toughness and fatigue performance of a thermosetting epoxy polymer

“…Barber et al [59] reported G i values of between 13 and 34 J/m 2 from Zhandarov et al [63] for glass fibres and vinyl ester (which is quite similar to the epoxy used here). They also reported values for CNTs and polyethylene-butane of a similar magnitude.…”

Adhesional pressure as a criterion for interfacial failure in fibrous microcomposites and its determination using a microbond test

“…Many papers have been published in support of each, referring both to different theoretical models of interfacial failure and experimental results obtained in micromechanical tests. In our papers [18,26,32,[57][58][59], we consistently support the conclusion that these two parameters can equally well describe the behavior of real interfaces in micromechanical tests, but neither of them can be regarded as a ''universal'' or ''true'' interfacial parameter which is constant under any conditions.…”

“…Which criterion better describes interfacial failure in the microbond test, can only be verified experimentally. The first two criteria (s d and G ic ) have been repeatedly compared in the literature [32,57,59], and it has been found that the local IFSS failure criterion gives better results for initiation of debonding than the critical energy release rate criterion but the situation may be different for analysis of propagation of debonding. In this context, 'better results' means the independence of the specimen geometry as well.…”

“…The 'equivalence' of these interfacial parameters as failure criteria was discussed in detail in Refs. [12,26,32,[57][58][59] (crack initiation) and Ref. [12,59] (crack propagation).…”

“…[12,26,32,[57][58][59] (crack initiation) and Ref. [12,59] (crack propagation). It was found that for crack propagation, especially at advanced stages of debonding (large crack lengths), the energy-based criterion (Gic) gives the best fit to experimental data from micromechanical tests [12,57,59]; in this paper, this can be clearly seen, e.g., in Fig.…”