On the critical conditions of kink band formation in fiber composites with ductile matrix

Continuum-mechanical modelling of kink-band formation in fibre-reinforced composites

“…The initiation stress is known to be quite sensitive to imperfections such as initial waviness or misalignment of fibres and fibre breakage due to micro-buckling, but the constant propagation stress, at which the kinked fibres ''lock-up'' into a fixed orientation and the kink band may propagate steadily, seems to be a material property independent of such imperfections. For various engineering theories that are aimed at predicting the initiation stress, the propagation stress, the kink orientation angle and the fibre direction within the kink band, we refer the reader to Yin (1992), Grandidier et al (1992), Guynn et al (1992), Fleck (1993, 1994), Chung and Weitsman (1995), Schapery (1995), Dao and Asaro (1996), Fleck (1997), Jensen and Christoffersen (1997), Kyriakides and Ruff (1997), Vogler and Kyriakides (1997), Budiansky et al (1998), Berbinau et al (1999), Hsu et al (1999), Jensen (1999), Drapier et al (2001), , and the references therein. We also mention the papers by Hunt et al (2000) and Wadee et al (2004) that are concerned with kink-band instability in layered structures in which sliding is permitted between the layers.…”

Rate dependent constitutive modelling of laminated FRP composites degraded by fire

“…The parameter β represents are frictional resistance due to the compaction of fabric due to normal compressive stresses. Note that as shown by Asaro and Rice (1977) and then again by Dao and Asaro (1996) the appearance of such terms in the loading parameter represents a deviation from the law of normality which, in turn, has implications for localized deformation. The constitutive description of the plasticity on each slip system is cast in terms of the resolved shear stress on that system and on the current slip rate on that system as,γ…”