“…Remote from local discontinuities/cracks, microstructural anomalies and/or other sources of strain gradients, it may be expected that the Voigt [60] isostrain assumption applies to the material and the strains reported by DVC are a good estimate of both fibre and matrix deformation; with the latter being the dominant contributor, as it contains the fiducial markers used to achieve reliable correlation (Appendix A). However, immediately adjacent to fibre breaks, steep strain gradients are expected, and may be influenced by the following mechanisms, or combinations thereof: (1) matrix plastic yielding [21], [22], [23] (2) fibre-matrix interfacial debonding (with slippage) [22], [23], [61], [62], [63], [64] (3) matrix microcracking [64], [65], [66], [67], and (4) fibre unloading and spring-back [3], [68], [69], [70]. The relative displacement of the edge-enhanced fibre ends [42] is also expected to contribute to the measured strain field.…”