Experimental Investigation of Strength of Curved Beam by Thin Ply Non-Crimp Fabric Laminates

Abstract

Resistance against delamination failure and through the thickness tensile properties of curved carbon fiber reinforced plastics composites are investigated experimentally by conducting the curved beam strength tests. Effect of novel material thin ply non crimp fabric (NCF) architecture on delamination resistance of carbon fiber reinforced composites are investigated and compare with that of standard UD layups. In order to determine through the thickness tensile properties of curved carbon fiber composites, standard test method is carried out, namely four-point bending tests. The dynamic delamination propagation and failure sequences under curved beam bending is captured using Photron© Fastcam SA5 ultra high speed system. For the non-crimp fabric configuration an increase in the curved beam strength is observed in comparison with [0] and [0/45/-45/0] laminates by unidirectional (UD) tape material. For the UD tape, the initial defects caused by the out-of-autoclave manufacturing process is found to be the potential failure sites. The test results and observations suggest that thin-ply NCF is much less vulnerable to the existence of manufacturing voids in contrast to standard thickness UD tape. Finally, TPNCF is shown to have superior properties in regard to delamination resistance and curved-beam strength.