Large Area Detection of Microstructural Defects with Multi-Mode Ultrasonic Signals

Journal Article · 17 February 2022 · Applied Sciences

DOI: https://doi.org/10.3390/app12042082 · OSTI ID:1893671

Ju, Taeho  ^[1]; Findikoglu, Alp Tugrul  ^[1]

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1. Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)

Cyclic loading or other stresses can lead to development of cracks and crack growth in mechanical structures, leading to eventual failure. While ultrasound imaging can be used for non-destructive testing of such structures, conventional ultrasound techniques are often limited by crack size, density, and areal coverage. An effective characterization of real-world, large-area structures is required at an early damage stage to prevent catastrophic failure and predict remaining life. In this study, a new nonlinear ultrasonic testing (NUT) method is proposed for large-area monitoring of practical structures with arbitrary complexity by using multiple-mode guided-wave ultrasonic signals. The proposed guided-wave NUT technique requires single-element transducers, simple electronics, and a mixed time-frequency domain signal processing. As a proof-of-concept demonstration, numerical simulations and experiments are performed on an A36 carbon steel beam assembly with previously formed microstructural defects that cause nonlinearities in ultrasonic response. The quadratic dependence of the nonlinear wave excitation on the input ultrasonic signal amplitude is shown by numerical simulations, and such a nonlinear ultrasonic response is experimentally observed in the zone with a high density of microstructural defects.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• Grant/Contract Number: 89233218CNA000001
• OSTI ID: 1893671
• Report Number(s): LA-UR-21-30162
• Journal Information: Applied Sciences, Journal Name: Applied Sciences Journal Issue: 4 Vol. 12; ISSN 2076-3417
• Publisher: MDPICopyright Statement
• Country of Publication: United States
• Language: English