Guided wave detection using different fiber optic sensors and their applications in damage detection for composite laminates were systematically investigated and compared in this paper. Two types of fiber optic sensors, namely fiber Bragg gratings (FBG) and Doppler effect-based fiber optic (FOD) sensors, were addressed and guided wave detection systems were constructed for both types. Guided wa...

ompetent performance of an ultrasound examination of any type is reliant on an understanding of the basic physical principles that govern the production of ultrasound waves and their interaction with biological tissues of differing densities and consistencies. It is also necessary to understand the basic concepts of how the ultrasound systems work and the concepts underlying their manipulation ...

This paper evaluates the benefits of using ultrasonic guided waves for mapping a structure, when implemented on mobile magnetic robotic platform. It considers specific problem geometric features waves, which enables localisation edges and/or welded joints. Shear Horizontal (SH) generated by Electro-Magnetic Acoustic Transducers (EMATs) are used steel samples with nominal thickness 10 mm. A Baye...

Early detection of defects inside a rail is great significance to ensure the safety transit. This work investigated ability ultrasonic guided waves (UGWs) detect internal in head. First, model UGW propagation rail, which has an irregular cross-section, was constructed based on semi-analytical finite element (SAFE) method. Fundamental characteristics, such as wavenumber, phase or group velocity,...

We propose a novel recurrence plot-based approach, the difference plot (DRP), to detect small deviations between measurements. By using prototypical model system, we demonstrate potential of DRPs and alternative measures, such as Pearson correlation, spectral analysis, or cross joint analysis. Real-world data comes from an application guided ultrasonic waves for structural health monitoring dam...

In this paper the Semi-Analytical Finite Element (SAFE) method for modeling guided wave propagation is extended to account for linear viscoelastic material damping. Linear viscoelasticity is introduced by allowing for complex stiffness constitutive matrices for the material. Dispersive characteristics of viscoelastic waveguides, such as phase velocity, attenuation, energy velocity and cross-sec...

To improve the defect detectability of Lamb wave inspection systems, the application of nonlinear signal processing was investigated. The approach is based on a Warped Frequency Transform WFT to compensate the dispersive behavior of ultrasonic guided waves, followed by a Wigner-Ville time-frequency analysis and the Hough Transform to further improve localization accuracy. As a result, an automa...

Non-Destructive Testing of industrial components carries vital importance, both financially and safety-wise. Among all Non-Destructive techniques, Long Range Ultrasonic Testing utilizing the guided wave phenomena is a young technology proven to be commercially valid. Owing to its well-documented analytical models, Ultrasonic Guided Waves has been successfully applied to cylindrical and plate-li...