Abstract

Fiber-metal laminates (FML) are hybrid materials that consist of alternating layers of metal and fiber-reinforced prepreg. The classical plane-stress theory has dificulty in dealing with the fatigue fracture of such materials where the crack only grows in the metal layers, while the prepreg layers remain intact. In this paper, a new theoretical treatment is given to FML under generalized plane-stress conditions. The new theory introduces a harmonic anti-plane-stress potential p to describe the interlaminar stresses near the crack tips and the “bridging” effect of the unbroken fibers along the crack wakes. An analytical solution is derived for GLARE-3 (3 ∕ 2) containing collinear cracks with length 2a₀ (the initial crack length) in the prepreg and length 2a in the aluminum layer. The effective stress intensity factor is obtained in a closed form, and the theoretical prediction is compared with the experimental behavior obtained from fatigue crack growth testing of center-notched specimens.

Keywords

fiber-metal laminate, stress intensity factor

Authors