Akademik Veri Yönetim Sistemi
3rd International Workshop on Plasticity, Damage and Fracture of Engineering Materials, IWPDF 2023, İstanbul, Türkiye, 4 - 06 Ekim 2023, cilt.61, ss.291-299
In this paper, an experimental investigation of the failure mechanism in fabric curved composite laminates having a stacking sequence of [(45/0)7/45/45/0/45] is presented. The curved beam specimens are manufactured from AS4/8552 5 Harness Satin Fabric prepregs. The experiments were carried out with a novel test fixture designed to apply pure shear loading to one arm of the curved specimen while the other arm is fixed. The high-speed camera (HSC) is utilized to observe the mechanism of the failure occurring on the curved beam. Afterward, the crack-tip speeds are calculated using the HSC images obtained with 420,000 frame per second. Fractography was conducted with post-mortem specimens using a digital microscope to assess the type and propagation of cracks in the curved region. All curved fabric specimens exhibited failure through one major crack located in the region of high radial stresses, leading to a loss of their load-carrying capacity. HSC observations show that the crack tips reach intersonic speed, exceeding the shear wave speed, indicating that the failure event occurring on the curved region of the beam is highly dynamic. Fluctuations occurring in the crack tip speed history are also observed. The micrographs show multiple crack initiations across different plies. It is observed that the crack propagation is influenced by the weave style of the fabric specimen, which may lead to the observed fluctuations in the crack tip speed history.