An Automatic Mode Separation Technique for Multimodal Guided Wave Analysis

Ultrasonic Guided Wave inspection is one of the most recent approaches of Non-Destructive Testing. The greatest challenge for any guided wave system is the plethora of wave modes arising from the complex geometry of the structural element which propagate with a range of frequency dependent velocities. As a result, multiple wave modes reflected by discontinuities in the structural element are combined to confuse the inspection. In this paper an automatic, novel signal processing technique is presented using a dispersion simulation and two dimensional subtractive search. The technique is applied to modeling data in order to separate superposed guided wave signals in time domain and derive the exact time of flight for individual wave modes

Keywords:

Structural Health Monitoring (SHM) , Guided Waves , Long Range Ultrasonic Testing (LRUT) , Non-Destructive Testing (NDT) , Wave Mode Separation.