Title

Ultrasonic Lamb Wave Nde Actuation and Sensing Study

Author(s)

Jared PetersFollow

School Name

South Carolina Governor's School for Science & Mathematics

Grade Level

12th Grade

Presentation Topic

Engineering

Presentation Type

Mentored

Abstract

A new methodology in safety standards is the use of Lamb Wave nondestructive evaluation (NDE). This technique allows for the examination of metal and composite structures from both inside and out to detect damage. The experiment discussed here used a 1 mm-thick aluminum plate with a bonded piezoelectric wafer activated sensor (PWAS) and a scanning laser Doppler vibrometer (SLDV) for detection. Quartz rods with diameters of 4 mm, 6 mm, and 8 mm were attached to the plate at 50 mm from the PWAS and bonded to the surface using rubber cement. An arbitrary waveform generator combined with an amplifier excited a 120 kHz tone-burst signal that activated the PWAS to create the Lamb wave signal in the plate. The SLDV used a line scan, where it scans multiple points in a 1-mm-diameter line from 0 to 100 mm from the PWAS, to collect the out-of-plane wave data from the excited wave. In order to process the results, the team calculated the Transmission and Reflection factors. The experiment found that increasing diameter of the damage (the quartz rod) leads to an increase in amplitude of the reflected wave and a decrease in the amplitude of the transmitted wave. The results were consistent with previous findings, and this allows the system to be further verified as a viable source of damage detections. Better understanding of this technique allows for improved testing in the future, and thus advances safety across many industries.

Location

Johns Hall 109

Start Date

3-28-2020 11:30 AM

Presentation Format

Oral Only

Group Project

No

COinS
 
Mar 28th, 11:30 AM

Ultrasonic Lamb Wave Nde Actuation and Sensing Study

Johns Hall 109

A new methodology in safety standards is the use of Lamb Wave nondestructive evaluation (NDE). This technique allows for the examination of metal and composite structures from both inside and out to detect damage. The experiment discussed here used a 1 mm-thick aluminum plate with a bonded piezoelectric wafer activated sensor (PWAS) and a scanning laser Doppler vibrometer (SLDV) for detection. Quartz rods with diameters of 4 mm, 6 mm, and 8 mm were attached to the plate at 50 mm from the PWAS and bonded to the surface using rubber cement. An arbitrary waveform generator combined with an amplifier excited a 120 kHz tone-burst signal that activated the PWAS to create the Lamb wave signal in the plate. The SLDV used a line scan, where it scans multiple points in a 1-mm-diameter line from 0 to 100 mm from the PWAS, to collect the out-of-plane wave data from the excited wave. In order to process the results, the team calculated the Transmission and Reflection factors. The experiment found that increasing diameter of the damage (the quartz rod) leads to an increase in amplitude of the reflected wave and a decrease in the amplitude of the transmitted wave. The results were consistent with previous findings, and this allows the system to be further verified as a viable source of damage detections. Better understanding of this technique allows for improved testing in the future, and thus advances safety across many industries.