The in-situ sensor-guided process characterization of advanced composite materials

This article describes the multifunctional use of fibers as reinforcements and acoustic waveguides for sensing the fiber-matrix interfacial conditions during processing. It is shown that monitoring the ultrasonic signal response through a reinforcing fiber in a composite material yields on-line information that is related to the densification of the composite in the vicinity of the interface. Leakage of ultrasound from the fiber to the matrix is shown to be function of the density of the matrix at the interface. It is also shown that these data can then be used to feed back to the process for optimization and control.