NOVEL CARBON NANOTUBE INTERLAMINAR FILM SENSORS FOR SKIN/STRINGER INTERFACE DAMAGE DETECTION IN CARBON COMPOSITE PANELS

摘要

Many composite components in aerospace or aircraft structures are made of flat or curved panels combined with adhesively bonded or co-cured frames and stiffeners. Stiffened carbon fiber composite panels are a typical form of composite structures for a variety of load carrying conditions due to their high weight-specific mechanical properties. External loadings will lead to different modes of failures ranging from micro- to macro-levels and affect the structural performance of the composite panels. This paper discusses the application of carbon nanotube interlaminar film sensors for damage and debonding detection of the skin/stringer interface in stiffened carbon fiber composite panels. The panels were subjected to tensile, three-point bending and drop-weight impact tests and the electrical-mechanical response of the carbon nanotube film sensors was measured in situ. The damage development and progression of the skin/stringer interface was also monitored and examined with the aid of acoustic emission and ultrasonic C-scan methods. The results show that the carbon nanotube interlaminar film sensors are highly capable of detecting the location and extent of damage occurring in the skin/stringer interface.