Transient Propagation and Scattering of Quasi-Rayleigh Waves in Plates: Quantitative comparison between Pulsed TV-Holography Measurements and FC(Gram) elastodynamic simulations

We study the scattering of transient, high-frequency, narrow-band quasi-Rayleigh elastic waves by through-thickness holes in aluminum plates, in the framework of ultrasonic nondestructive testing (NDT) based on full-field optical detection. Sequences of the instantaneous two-dimensional (2-D) out-of-plane displacement scattering maps are measured with a self-developed PTVH system. The corresponding simulated sequences are obtained by means of an FC(Gram) elastodynamic solver introduced recently, which implements a full three-dimensional (3D) vector formulation of the direct linear-elasticity scattering problem. A detailed quantitative comparison between these experimental and numerical sequences, which is presented here for the first time, shows very good agreement both in the amplitude and the phase of the acoustic field in the forward, lateral and backscattering areas. It is thus suggested that the combination of the PTVH system and the FC(Gram) elastodynamic solver provides an effective ultrasonic inspection tool for plate-like structures, with a significant potential for ultrasonic NDT applications.Comment: 46 pages, 16 figures, corresponding author Jos\'e Carlos L\'opez-V\'azquez, [email protected]. Changes: 1st, 4th, 5th paragraphs (intro), 3rd, 4th paragraphs (sec. 4); [59-60] cited only in appendixes; old ref. [52] removed; misprints corrected in the uncertainty of c_L (subsec. 3.1), citation to fig. 10 (sec. 4), size of images (caption fig.15); reference to Lam\'e constants removed in subsec. 3.

Numerical modeling and measurement by pulsed television holography of ultrasonic displacement maps in plates with through-thickness defects

We present a novel numerical modeling of ultrasonic Lamb and Rayleigh wave propagation and scattering by through-thickness defects like holes and slots in homogeneous plates, and its experimental verification in both near and far field by a self-developed pulsed TV holography system. In contrast to rigorous vectorial formulation of elasticity theory, our model is based on the 2-D scalar wave equation over the plate surface, with specific boundary conditions in the defects and plate edges. The experimental data include complex amplitude maps of the out-of-plane displacements of the plate surface, obtained by a two-step spatiotemporal Fourier transform method. We find a fair match between the numerical and experimental results, which allows for quantitative characterization of the defects

Modelling for characterizing defects in plates using two-dimensional maps of instantaneous ultrasonic out-of-plane displacement obtained by pulsed TV-holography

It has been demonstrated that non-destructive inspection of plates can be performed by using two-dimensional maps of instantaneous out-of-plane displacements obtained with a self-developed pulsed TV-holography system. Specifically, the interaction of guided elastic waves with defects produces scattering patterns that contain information about the defects (position, dimensions, orientation, etc.). For quantitative characterization on this basis, modeling of the wave propagation and interaction with the defects is necessary. In fact, the development of models for scattering of waves in plates is yet an active research field in which the most reliable approach is usually based on the rigorous formulation of elasticity theory. By contrast, in this work the capability of a simple two-dimensional scalar model for obtaining a quantitative description of the output two-dimensional maps associated to artificial defects in plates is studied. Some experiments recording the interaction of narrowband Rayleigh waves with artificial defects in aluminum plates are presented, in which the acoustic field is obtained from the TV-holography optical phase-change maps by means of a specially developed two-step spatio-temporal Fourier transform method. For the modeling, harmonic regime and free-stress boundary conditions are assumed. Comparisons between experimental and simulated maps are included for defects with different shapes

Transient Propagation and Scattering of Quasi-Rayleigh Waves in Plates: Quantitative comparison between Pulsed TV-Holography Measurements and FC(Gram) elastodynamic simulations

We study the scattering of transient, high-frequency, narrow-band quasi-Rayleigh elastic waves by through-thickness holes in aluminum plates, in the framework of ultrasonic nondestructive testing (NDT) based on full-field optical detection. Sequences of the instantaneous two-dimensional (2-D) out-of-plane displacement scattering maps are measured with a self-developed PTVH system. The corresponding simulated sequences are obtained by means of an FC(Gram) elastodynamic solver introduced recently, which implements a full three-dimensional (3D) vector formulation of the direct linear-elasticity scattering problem. A detailed quantitative comparison between these experimental and numerical sequences, which is presented here for the first time, shows very good agreement both in the amplitude and the phase of the acoustic field in the forward, lateral and backscattering areas. It is thus suggested that the combination of the PTVH system and the FC(Gram) elastodynamic solver provides an effective ultrasonic inspection tool for plate-like structures, with a significant potential for ultrasonic NDT applications

Experiencias de aprendizaje

Libro de experiencias de aprendizaje del grupo de investigación Giteca y de los semilleros de investigación en la que se visualizan las diferentes experiencias lideradas por instructores y aprendices en las diferentes áreas y líneas de formación.Book of learning experiences of the Giteca research group and the research hotbeds in which the different experiences led by instructors and apprentices in the different areas and lines of training are visualized.Propagación in vitro como un camino de aprendizaje para la formación profesional integral -- Experiencias significativas de aprendizaje, laboratorio de hematología y parasitología animal del Complejo Tecnológico para la Gestión Agroempresarial CTPGA-SENA -- Experiencias significativas adquiridas por aprendices en el área de SENNOVA, Complejo Tecnológico para la Gestión Agroempresarial. Regional – Antioquia -- El papel de la prensa escrita en el desarrollo de la competencia textual -- Aprendiendo a Emprender con un emprendedor -- Ven y te cuento sobre ADSI -- Observaciones fenológicas del cultivo de cacao (Theobroma cacao) en los municipios de Tarazá, El Bagre y Caucasia dentro de la formación del programa SENA emprende rural -- Tejiendo sueños desde la formación -- Forraje verde hidropónico como alternativa para disminuir la expansión de la frontera agrícola en el Putumayo -- La importancia del saber hacer para ser competente en el sector agrícola -- Experiencia significativa de aprendizaje semilleros de investigación -- La investigación como ente transformador de pensamientos -- Piscícola Paraguay; Mi Sueño, Mi Proyecto de Vida! -- Estrategia de aprendizaje a través de la investigación y la empresa aplicando un programa de Responsabilidad Social Empresarial –RSE -- Matemática aplicada para procesos agroindustriales de panificaciónna85 página

Transient Propagation and Scattering of Quasi-Rayleigh Waves in Plates: Quantitative comparison between Pulsed TV-Holography Measurements and FC(Gram) elastodynamic simulations

We study the scattering of transient, high-frequency, narrow-band quasi-Rayleigh elastic waves by through-thickness holes in aluminum plates, in the framework of ultrasonic nondestructive testing (NDT) based on full-field optical detection. Sequences of the instantaneous two-dimensional (2-D) out-of-plane displacement scattering maps are measured with a self-developed PTVH system. The corresponding simulated sequences are obtained by means of an FC(Gram) elastodynamic solver introduced recently, which implements a full three-dimensional (3D) vector formulation of the direct linear-elasticity scattering problem. A detailed quantitative comparison between these experimental and numerical sequences, which is presented here for the first time, shows very good agreement both in the amplitude and the phase of the acoustic field in the forward, lateral and backscattering areas. It is thus suggested that the combination of the PTVH system and the FC(Gram) elastodynamic solver provides an effective ultrasonic inspection tool for plate-like structures, with a significant potential for ultrasonic NDT applications