Mechanical Properties and Fatigue Responses of Fiber Metal Nanocomposite
Laminates with Double-Edged Cracks
Abstract
The fiber metal laminates (FMLs) of both Ti/APC-2 neat and nanocomposite
laminates were fabricated. The double-edged cracks of both symmetry and
anti-symmetry were cut in FMLs. From tensile tests we received the load
vs. displacement curves and mechanical properties. From cyclic tests the
load vs. cycles (P-N) curves, residual life, and failure mechanisms were
obtained. The mechanical properties of symmetrically cracked specimens
were slightly lower than those of anti-symmetrically cracked
counterparts. As the crack length increasing and inclined angle
decreasing, the fatigue life decreased. The enhancement of nano-powder
improved the ultimate load and fatigue life. The local stress intensity
at the crack tip dominates the fatigue responses. The piece of
elliptical part was observed from cyclic tests at failure. Although the
attraction of two crack tips accelerated the crack growth rate, however,
the delay to failure was caused by forming a small piece of ellipse
centrally.