Bianchi, FrancescoZhang, Xiang2012-07-312012-07-312012-05-02Francesco Bianchi and Xiang Zhang. Predicting mode II delamination suppression in z-pinned laminates. Composites Science and Technology, Volume 72, Issue 8, 2 May 2012, Pages 924-9320266-3538http://dx.doi.org/10.1016/j.compscitech.2012.03.003http://dspace.lib.cranfield.ac.uk/handle/1826/7472A finite element model for predicting delamination resistance of z-pin reinforced laminates under the mode-II load condition is presented. End notched flexure specimen is simulated using a cohesive zone model. The main difference of this approach to previously published cohesive zone models is that the individual bridging force exerted by z-pin is governed by a specific traction- separation law derived from a unit-cell model of single pin failure process, which is independent of the fracture toughness of the unreinforced laminate. Therefore, two separate traction-separation laws are employed; one represents unreinforced laminate properties and the other for the enhanced delamination toughness owing to the pin bridging action. This approach can account for the so-called large scale bridging effect and avoid using concentrated pin forces in numerical models, thus removing the mesh-size dependency and permitting more accurate and reliable computational solutions.en-UKArticle