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Laser Ultrasonic Technique for Simultaneous Measurement of Thickness, Slope, and Wave Velocities for Slope Plate in the Thermoelastic Regime

Dung Nguyen Tien, Arai Yoshio

Advances in Science and Technology. Research Journal

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2024

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Vol. 18, no 5

EN

This study introduces a reliable method for simultaneously determining the thickness, slope, and ultrasonic velocities of slope plates using laser ultrasonic techniques without any damage in the thermoelastic regime. The method involves solving a system of equations to determine the arrival times of multiple signals displayed on a waveform. Numerical simulations indicate that the velocity of the skimming longitudinal wave remains constant when the Rayleigh wave does not overlap with its signal. Consequently, a prediction model for aluminum alloy has been established, enabling the estimation of the constant ratio between the velocities of skimming longitudinal and bulk longitudinal waves based on the skimming longitudinal velocity obtained by scanning the generating laser along the material's surface. This ratio, approximately 0.950, facilitates the combination of the skimming longitudinal wave with the reflected and mode-converted waves from the specimen's back surface to deduce the desired parameters. The method successfully determined the thickness, slope, and wave velocities of several specimens with slopes ranging from 0% to 1.96% and a maximum thickness of about 10 mm. Evaluating the influence of the size of the disk ultrasound source produced by the unfocused laser beam, we found that the radius of the disk source should be considered when calculating the arrival time of the skimming longitudinal wave. The root mean square deviation in measuring thickness, slope, longitudinal wave velocity, and shear wave velocity were approximately 0.100 mm, 0.10 %, 70 m/s, and 20 m/s, respectively. An assessment of the measured results, based on the root mean square deviation and uncertainty across all specimens, demonstrates the practical feasibility of the proposed method.

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A new BEM for modeling and simulation of 3T MDD laser-generated ultrasound stress waves in FGA smart materials

Fahmy Mohamed A.

Computer Methods in Materials Science

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2021

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Vol. 21, No. 2

95--104

EN

The goal of this study is to present a new theory known as the three-temperature memory-dependent derivative (MDD) of ultrasound stress waves in functionally graded anisotropic (FGA) smart materials. It is extremely difficult to address the difficulties related to this theory analytically due to its severe nonlinearity. As a result, we suggest a new boundary element method (BEM) to solve such equations. The suggested BEM technique incorporates the benefits of both continuous and discrete descriptions. The numerical results are visually represented to demonstrate the impacts of MDD three temperatures and anisotropy on the ultrasound stress waves in FGA smart materials. The numerical findings verify the proposed methodology’s validity and accuracy. We may conclude that the offered results are useful for comprehending the FGA smart materials. As a result, our findings contribute to the advancement of the industrial applications of FGA smart materials.

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A new diagnosing method of the internal structure of the titanium fan of a jet engine with laser ultrasonics

Swornowski P.

Metrology and Measurement Systems

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2011

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Vol. 18, nr 3

441-451

EN

Advanced metallic material processes (titanium) are used or developed for the production of heavily loaded flying components (in fan blade construction). The article presents one process for diagnosing the blade interior by means of laser ultrasonography. The inspection of these parts, which are mainly made of titanium, requires the determination of the percentage of bonded grain sizes from around 10 to 30 žm. This is primarily due to the advantages of a high signal-to-noise ratio and good detection sensitivity. The results of the research into the internal blade structure are attached.