QUANTIFYING THE EFFECT OF FIBER BRIDGING ON MODE I QUASI-STATIC AND FATIGUE TESTING [Keynote]
This investigation focuses on mode I delamination propagation in a unidirectional (UD) carbon fiber reinforced polymer (CFRP) composite laminate. Delamination propagation in this type of material may be accompanied by fiber bridging, a phenomenon where fibers from one face of the delamination cross over to the other face, such that the fibers are simultaneously pulled from both faces, thus, bridging the delamination. This increases the material's apparent resistance to further propagation of the delamination. This phenomenon occurs mostly in beam-type test specimens commonly used to characterize failure of composite materials, but does not generally occur in structures with the exception a few structures such as rotor blades. The aim of this investigation is to quantify the effect of fiber bridging for quasi-static and fatigue testing of DCB specimens so as to eliminate it from the fracture and fatigue delamination propagation properties.