Topic: Mechanical Design of Ultrasonic Optical Strain Sensors
Speaker: Erik Frankforter, PhD Candidate, University of South Carolina
Date: Thursday, September 28, 2017
Location: NIA, Room 137
Time: 10:00am – 11:00am
Abstract: This talk outlines the development of ultrasonic optical strain sensors in which the mechanical housing has been designed to provide both increased sensitivity and qualitative sensing enhancements. Sensors are designed at roughly 3-12 mm in size and increased sensitivity on the order of 20 dB is provided through mechanical resonance principles. The sensors also mitigate some of the limitations in fiber optic sensing of ultrasonic elastic waves; fiber optic strain sensors which typically have a unidirectional response are made omnidirectional. The sensors are also configured to stay within their measurement range during structural loading by mechanically isolating the optical fiber from quasi-static strain. Two sensor configurations are discussed: a ring resonator and an “acoustic black hole” tapered thickness wave absorber. The entire sensor development process is discussed, from concept sketch through to modeling, design, verification, and calibration.
Bio: Erik Frankforter is a mechanical engineering Ph. D. candidate at the University of South Carolina with an emphasis in structural health monitoring and sensor development. His work focuses on aspects of sensor design which include finite element modeling of wave-sensor interaction, developing optimized sensor housings, and evaluating temperature effects on piezoelectric sensors. In his free time, he loves training in a martial art called Aikido and taking his dog, Voodoo, to the local state and national parks.