Effects of temperature and fiber orientation on mode Ⅱ interlaminar fracture behavior of carbon/epoxy composites

摘要

In the present study, end notched flexure (ENF) tests were performed to investigate the effects of temperature and fiber orientation on Mode Ⅱ interlaminar fracture behavior, G_(IIC)(G_(II) at the crack initiation), of carbon fiber-reinforced epoxy composites, T800H/#3631. The values of G_(IIC) for three kinds of laminates, [O_(12)//0_(12)], [22.5/-22.5/0_8/-22.5/22.5//-22.5/22.5/0_8/22.5/-22.5] and [45/-45/0_8/-45/45//-45/45/0_8/45/-45], with a pre-cracked interface, that is // in each laminate, were obtained at three temperatures, i.e., -100℃, 25℃ and 150℃. It is shown that G_(IIC) is obviously affected by the temperature and fiber orientation. The scanning electron microscope (SEM) observation was also carried out to investigate the fracture surface. SEM analysis suggested that the decreased Mode II interlaminar fracture toughness for all kinds of specimens at high temperature could be attributed to temperature-induced matrix property change or fiber-matrix interfacial weakening.