The quasi-static transverse fracture behavior in unidirectional fiber-reinforced composites (FRCs) is investigated using a new intermediately-homogenized peridynamic (IH-PD) model and a fully homogenized peridynamic (FH-PD) model. The novelty in the IH-PD model here is accounting for the topology of the fiber-phase in the transverse sample loading via a calibration to the Halpin-Tsai model. Both models can capture well the measured load-displacement behavior observed experimentally for intraply fracture, without the need for an explicit representation of microstructure geometry of the FRC. The IH-PD model, however, is more accurate and produces crack path tortuosity as well as a non-monotonic load-crack-opening softening curve, similar to what is observed experimentally. These benefits come from the preservation of some micro-scale heterogeneity, stochastically generated in the IH-PD model to match the composite’s fiber volume fraction, while its computational cost is equivalent to that of an FH-PD model. We also present a three-point bending transverse loading case in which the two models lead to dramatically different failure modes: the FH-PD model shows that failure always starts from the off-center pre-notch, while the IH-PD model, when the pre-notch is sufficiently off-center, finds that the composite fails from the center of the sample, not from the pre-notch. Experiments that can confirm these findings are sought.
An Energy-Based Model of Longitudinal Splitting in Unidirectional Fiber-Reinforced Composites