Mode II Shear Behavior of a Glass Fabric/Epoxy and a Multi Scale Glass Fabric/Epoxy Thick Beam Composite Containing Multiwalled Carbon Nanotubes

The mode II shear behavior of a glass fabric/epoxy composite and a multiscale hybrid glass fabric/epoxy composite containing Multi Walled Carbon Nano Tubes (MWCNT) are compared here in the interlaminar mode of loading. The thick composites were fabricated through the vacuum bagging technique and two sets of specimens were prepared with and without carbon nano tubes. One set of each of these specimens were prepared with a Teflon® film crack initiator at the end of the specimens exactly at the centroidal line of the laminate to study the fracture behavior and strain energy release rates. This study addresses the issue of testing thick laminated composites and thick multiscale laminated composites in Mode II Inter Laminar Shear (ILS). The Inter Laminar Shear Strengths (ILSS) of these composites were evaluated. The theories on the strain energy release rate are also revisited and useful conclusions drawn regarding the applicability of the same to multiscale composites loaded in the ILS test set up. Thus, a comparison is made between the mode II behavior in flexure and ILS of these composites.