Analysis of failure modes for a non-crimp basalt fiber reinforced epoxy composite under flexural and interlaminar shear loading

This study investigates the mechanical properties (inter laminar shear and flexural strength) and failure modes of a basalt/epoxy composite, manufactured using a non-crimp-fabric (NCF) with vacuum assisted resin infusion process. Under flexural bending, damage initiated on the compression side between 20 and 50% of peak load and progressed from ply to ply with increasing load. Failure at tension surface of the flexural bending specimen was confined to the bottom ply and was evident only close to final failure. Fibre kinking was the dominant failure mechanism on the compression side whereas fibre breakage was the dominant mechanism on the tension side. Regarding interlaminar shear, interlaminar shear cracks initiated once samples were subjected to stress levels above 50% of peak stress and grew until failure with the crack following the fibre matrix interface of 90 degree tows. Overall, comparing with values available in the open literature, the NCF basalt/epoxy composite outperformed plain-woven basalt/epoxy and plain-woven E-glass/epoxy composites in terms of both flexural and interlaminar shear strength but demonstrated lower strength than NCF E-glass/epoxy composite.