Operational and defect parameters concerning the acoustic-laser vibrometry method for FRP-reinforced concrete

• Acoustic-laser vibrometry is a non-contact method for non-destructive testing.
• Operational and defect parameters were studied to determine the effect on POD and measured signatures.
• Increasing acoustic excitation pressure level and increasing laser power best improve POD.
• Decreasing defect size and increasing defect curvature both increase defect resonant frequency.
• Defect aspect ratio affects resonant frequency spacing, slender defects have closer resonances.

Acoustic-laser vibrometry, a non-contact method for nondestructive testing, was studied by altering operational and defect parameters to determine their effects on measured signatures and system performance. The method detects delamination and voids in fiber-reinforced polymer reinforced concrete by vibrating the material with an acoustic excitation and measuring the vibration signature with a laser vibrometer. The operational parameters studied were excitation sound pressure level, laser signal, angle of incidence, and dwell time. The defect parameters studied were aspect ratio, size, and curvature. This study was undertaken to understand the method׳s phenomenology and to provide fundamental knowledge for an operational field system.