Geometric modelling of kink banding in laminated structures

Abstract

An analytical model founded on geometric and potential energy principles for kink band deformation in laminated composite struts is presented. It is adapted from an earlier successful study on confined layered structures that was formulated to model kink band formation in the folding of geological layers. This study's principal aim was to explore the underlying mechanisms governing the kinking response of flat, laminated components comprising unidirectional composite laminae. A pilot parametric study indicates that the key features of the mechanical response are captured well and that quantitative comparisons with experiments presented in the literature are highly encouraging.

Effects of thickness and fibre misalignment on compression fracture in cross-ply (very) long cylindrical shells under external pressure

“…It may be remarked that the computed value of 17.658 • is closer to elastic microbuckling of a unidirectional lamina withβ = 0 • . This is due to the reduced shear modulus of the lamina [37,45], making fibres more (relatively speaking) susceptible to microbuckling in the shear mode. Furthermore, these uniformly distributed fibre misalignments resemble the microbuckled state under shear mode.…”

“…More recently, Wadee et al [45] have presented a similar analytical model for investigating kink band-type instability in laminated composite struts.…”

Variational Modeling of Slip: From Crystal Plasticity to Geological Strata

“…Firstly, the model focuses on the early stages up to the formation of the first kink. An extended discussion of the development of the first few kink-bands, among other modifications and improvements to the basic model, is given in [WVHY12]. We also refer to [BFA98], where the focus lies on kink-band evolution, especially on band broadening and transverse kink-band propagation in fiber composites.…”

“…Secondly, the energy in (2.1) relies on the hypothesis that kinks form, as well as on a priori assumptions on the character of the kinks. The condition of fixed kink-band width is relaxed in both [WVHY12] and [BFA98], where it results from a minimizing procedure after adding a bending energy to the model, which leads to an intrinsic length scale.…”

“…The variational viewpoint outlined in Section 2.5.4 gives a new perspective on and complements the existing models in the field. A discrete model, which we describe in more detail in Section 2.3 and which serves us as a comparison, was introduced in [HPW00] and further developed and extended in [WHP04,WVHY12].…”