Multi-wave-mode, multi-frequency detectors for guided wave interrogation of plate structures

作者：Jarmer Gregory J S; Flynn Eric B; Todd Michael D^*

来源：Structural Health Monitoring-An International Journal, 2014, 13(2): 120-130.

DOI：10.1177/1475921713513972

• Guided ultrasonic waves
• Lamb waves
• generalized likelihood ratio test
• detection theory
• plate structures

The detection and localization of damage using an array of closely spaced transducers is investigated theoretically and experimentally using single- and multiple-mode guided wave active sensing models. Detectors are derived using a generalized likelihood ratio approach assuming that amplitude, absolute phase, and source location of a scattered wave are unknown, while frequency, group velocity, and phase velocity are known. Theoretical detection performance for processing with each detector is derived and related to the energy-to-noise ratio of a scattered mode as a metric of determining when processing with multiple modes provides increased performance over processing with a single mode. Experimentally, detectors are implemented to detect scattering from a small mass glued to the surface of an aluminum plate with a 7 x 7 array of transducers. Relative detection and localization performance is compared through receiver operating characteristic curves and histograms of distance from true damage location for 1000 no-damage and damaged measurements. A single-mode, multi-frequency detector is shown to have the best detection and localization performance for the tested damage scenarios.

• 出版日期2014-3