MAE PhD Defense – Tyler Hudson

A guided wave-based, in-process, cure monitoring technique for carbon fiber reinforced polymer (CFRP) composites was investigated. Two cure monitoring systems using ultrasonic, guided wave-based measurements were developed. In the first system, high-temperature piezoelectric transducers were employed for actuation and sensing. In the second system, piezoelectric discs, bonded to the surface of the composite, were utilized for excitation and fiber Bragg gratings (FBGs) and/or phase-shifted fiber Bragg gratings (PS-FBGs) for sensing.

Composite material properties (viscosity and degree of cure) of the panels fabricated from Hexcel® IM7/8552 prepreg were correlated to the amplitude, time of arrival, and group velocity of the guided wave-based measurements. In addition, key phase transitions (gelation and vitrification) during the cure cycle were clearly identified from the experimental data. The material properties and phase transitions were validated using cure process modeling software.

Tyler Blake Hudson graduated with a B.S. in Civil Engineering from North Carolina State University in December 2012 as the Valedictorian of Civil, Construction, and Environmental Engineering. In January 2013, he began graduate school under the advisement of Dr. Fuh-Gwo Yuan at North Carolina State University and graduated with a M.S. in Mechanical Engineering in May 2014. At this same time, he moved to Hampton, VA, to continue his research at NASA Langley Research Center towards a Ph.D. in Aerospace Engineering. His research has focused on the manufacturing, processing, structural health monitoring, and nondestructive evaluation of advanced aerospace composite structures.