A novel model of delamination bridging via Z-pins in composite laminates

作者：Allegri G^*; Yasaee M; Partridge I K; Hallett S R

来源：International Journal of Solids and Structures, 2014, 51(19-20): 3314-3332.

DOI：10.1016/j.ijsolstr.2014.05.017

• Composite materials
• Fibre reinforced
• Delamination
• Toughness

A new micro-mechanical model is proposed for describing the bridging actions exerted by throughthickness reinforcement on delaminations in prepreg based composite materials, subjected to a mixedmode (I-II) loading regime. The model applies to micro-fasteners in the form of brittle fibrous rods (Z-pins) inserted in the through-thickness direction of composite laminates. These are described as Euler-Bernoulli beams inserted in an elastic foundation that represents the embedding composite laminate. Equilibrium equations that relate the delamination opening/sliding displacements to the bridging forces exerted by the Z-pins on the interlaminar crack edges are derived. The Z-pin failure meso-mechanics is explained in terms of the laminate architecture and the delamination mode. The apparent fracture toughness of Z-pinned laminates is obtained from as energy dissipated by the pull out of the throughthickness reinforcement, normalised with respect to a reference area. The model is validated by means of experimental data obtained for single carbon/BMI Z-pins inserted in a quasi-isotropic laminate.

• 出版日期2014-10-1