Interlaminar Mode II Fracture Characterization

Delamination is an important concern in the context of structural behaviour of laminated composite materials. It is known that delamination can diminish the stiffness and the strength of the material and promote structural failure. Delamination onset and growth is governed by interlaminar fracture toughness of the material. Delamination propagation is frequently dominated by mode II fracture; consequently interlaminar fracture characterization under mode II loading is fundamental to accurately predict the susceptibility of the material to delamination. However, there are several problems inherent to the usual tests employed for mode II interlaminar fracture characterization, e.g., unstable crack propagation and difficulties in crack monitoring during propagation. These issues are discussed in section 1.