In this paper, a set of failure criteria for transverse failure in Non Crimp Fabric (NCF) reinforced composites are presented. The proposed failure criteria are physically based and take into account the orthotropic character of NCF composites addressing the observed lack of transverse isotropy. Experimental data for transverse loading out of plane in combination with inplane loads are scarce. Therefore, to validate the developed criteria, experimental data are complemented with numerical data from a representative volume element (RVE) model using a meso-micromechanical approach. The RVE model also provides a deeper understanding of how failure occurs in NCF composites. Strength predictions from the developed set of failure criteria show good agreement with the experimental and numerical data.
Kink-band formation is the governing failure mechanism for compressive failure of fibre reinforced composites. Here, kink-plane orientation, describing the direction of kink-band formation, is studied using X-ray computed tomography (CT). Unnotched unidirectional specimens with off-axis angles ranging from 0-20 • are tested in compression. The measured compressive strength is found practically constant for off-axis angles between 0-10 •. For an off-axis angle of 15 • the compressive strength drops dramatically. CT-results reveal this drop to be consistent with a transition from out-of-plane to in-plane dominated kinking. Furthermore, results show the kink-plane angle to be linearly dependant on off-axis angle, and hence in-plane shear stress. A three-dimensional finite element model considering measured fibre misalignment angles through its volume is generated for numerical analysis. Numerical predictions based on the LaRC05 kinking criterion are found to qualitatively capture the experimentally observed effects of off-axis angle on kink-plane orientation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.