Rate effects on fiber–matrix interfacial transverse debonding behavior

Abstract

The rate effect of fiber–matrix interfacial debonding behavior of SC-15 epoxy with S-2 glass and aramid fiber reinforcements was studied via in-situ visualization of the transverse debonding event. In this study, the debonding force history, debonding initiation, debonding crack velocity, and crack geometry were characterized using a quasi-static load frame and a modified tension Kolsky bar at loading velocities of 0.25 mm/s and 2.5 m/s. Cruciform-shaped specimens were used for interfacial transverse debonding between SC-15 epoxy matrix and two types of fiber reinforcements. The load history and high-speed images of the debonding event were simultaneously recorded. A major increase was observed for the average peak debonding force and a minor increase was observed for the average crack velocity with increasing loading velocity. The crack geometry of the cruciform specimens under both loading velocities was also tracked. Scanning electron microscopy of the recovered specimens revealed the debonding direction along the fiber–matrix interface through angled patterns on the failure surface.

Measuring the Effect of Strain Rate on Deformation and Damage in Fibre-Reinforced Composites: A Review

“…Applying a high strain rate tensile load to a single fibre [28] is arguably the simplest such approach, and novel diagnostic options include imaging of a SHPB-driven experiment using a synchroton's x-ray beamline [29]. Chu et al designed a pull-apart test for a similar glass/epoxy specimen, showing that the debonding force increased by 81% from quasistatic to high strain rate loading, while the crack velocity increased by 16% [30]. There are also many examples of quasistatic fibre-matrix interface experiments, such as Favre & Merienne's pull-out assessment of fibre coatings [31].…”

Transverse Loading on Single High-Performance Fibers by Round-Head Indenters and the Fibers’ Failure Visualization

“…For example, transverse impact on yarns [1,2], composite strips [3], composite single plies [4], fabrics [5], and laminates [6] revealed a punch-shear failure mechanism at the critical velocity or ballistic limit, indicating that fibers are not under a pure-tension stress state. Besides, fractography on several fibers after transverse debonding with matrix [7] showed that aramid fibers were split transversely during debonding. In contrast, S-2 glass fibers debonded with the matrix along their interfaces.…”