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Borate Phosphors for Neutron Radiography
Published in S. K. Omanwar, R. P. Sonekar, N. S. Bajaj, Borate Phosphors, 2022
Radiography is a non-destructive testing method that produces an image using penetrating radiation, such as X-rays or neutrons, instead of visible light. The attenuation of a radiation beam passing through an object reveals clues about the internal structure of that object. Among various applications of neutrons, neutron radiography (NR) holds a special place. It was developed much later following several other applications like neutron activation analysis (NAA), isotope production, crystallography using neutron diffraction, etc. One of the reasons is that NR requires a special type of equipment and trained personnel, the requirement arising out of safety measures to be taken against the possible hazards. Radiography with gamma rays and X-rays has been long established as a very important technique of non-destructive testing, but the use of neutrons is only just becoming prominent.
Robotic Electromagnetic Eddy Current Testing Technique
Published in Chunguang Xu, Robotic Nondestructive Testing Technology, 2022
Electromagnetic eddy current testing is based on the principle of electromagnetic induction and is widely used in the nondestructive testing (NDT) of conductive materials [1]. This technique, together with the associated equipment, is widely used in aerospace, metallurgy, machinery, electric power, chemical industry and other fields, thus playing an increasingly important role. Compared with ultrasonic testing (UT), X-ray testing and penetrant testing, this testing technique has its own characteristics. Through the combination with single-manipulator scanning technique, it can achieve satisfactory non-contact automatic scanning. By increasing the eddy current detection frequency, it can detect the defects on or near surface and avoid the need for water coupling (like in NDT) to realize high-frequency UT [2,3]. It is especially suitable for in situ testing.
Nondestructive high-sensitivity magnetic detection of corrosion in light pole bases
Published in Hiroshi Yokota, Dan M. Frangopol, Bridge Maintenance, Safety, Management, Life-Cycle Sustainability and Innovations, 2021
T. Ishikawa, K. Tsukada, H. Furuta
The Eddy-current Testing or Electromagnetic Testing (E.T) is often used as a nondestructive testing for detection of surface flaws. However, the E.T cannot be applied to detection of inner corrosion of steel structures. A nondestructive high-sensitivity magnetic measurement technology under a SIP project of “nondestructive high-sensitivity magnetic inspection for assessment of infrastructure deterioration and maintenance planning” (Keiji Tsukada, research and development officer, Okayama University) was a new technology for nondestructive measurement of the amount of corrosion in a steel plate. Extremely Low-Frequency Eddy Current Testing with Spectrum Analysis of Magnetic field (ELECT-SAM) was developed for detection of inner corrosion of steel structures (Tsukada et al. 2016, 2017 and 2018). Figure 2 shows the system of ELECT-SAM. This nondestructive testing system can detect inner corrosion by extremely low frequency with employing a magnetic probe using an anisotropic magnetic resistance (AMR) sensor. To inspect the inner defects of the steel plate, a low frequency of eddy current testing is required (Tsukada et al. 2016 and Akutsu et al. 2018). In this system, to estimate the remaining plate thickness, the calibrated equations obtained by magnetic spectrum analysis are prepared. The probe of conventional ELECT-SAM was assumed to the perpendicular to the surface of the steel plate, as shown in Figure 3(a).
Scattering of SH guided wave by a circular cavity in a strip with the serrated boundary
Published in Waves in Random and Complex Media, 2022
The plate-shell material and the structure have a wide application in the production and the living practice, the dynamic stress concentration caused by the scattering of elastic wave at the defects of the cylindrical cavity in the serrated boundary strip medium have a great influence on the engineering application of such materials and structures. At the same time, the propagation of SH wave in the strip-shaped medium and the scattering problem of the circular cylindrical cavity are also one of the research directions of the elastic dynamics. Non-destructive testing (NDT) is commonly used to detect defects in material without damaging the material or making it unsuitable for use. And SH wave scattering is an important topic to be discussed in the application of NDT. In conclusion, the research of the anti-plane steady-state response to the cylindrical cavity in the strip-shaped medium is of theoretical and engineering significance. The study of elastic waves is a traditional field of solid mechanics. In the past 100 years, in addition to P and S waves, Rayleigh surface waves and Lamb waves in the strip have also been deeply studied and widely applied. In contrast, there are few studies on SH wave. In fact, the earliest SH wave (Love wave, 1911) was discovered earlier than Lamb wave (1917). Compared to SV waves, the zero-order SH wave (SH0) is the only non-dispersing guided wave in the strip. Thanks to this property, it is as convenient for calculation and analysis and signal processing as body wave, and has a good application prospect in the field of structural health monitoring (SHM).
Technical Note: The Anti-plane Scattering of SH Waves by the Non-circular Cavity in an Infinite Strip
Published in Journal of Earthquake Engineering, 2022
The plate-shell material and the structure have a wide application in the production and the living practice, the dynamic stress concentration caused by the scattering of elastic wave at the defects of the cavity has a great influence on the engineering application of such materials and structures. In this paper, the anti-plane problem in plates with a circular cavity defect and non-circular cavity defect can be regarded as the steady-state scattering of SH waves by cavity defect in infinite strip media, then to solve it. At the same time, the propagation of SH waves in the strip-shaped medium and the scattering problem of the circular cavity are also one of the research directions of the elastic dynamics. Non-destructive testing (NDT) is commonly used to detect defects in the material without damaging the material or making it unsuitable for use. And SH wave scattering is an important topic to be discussed in the application of NDT. In conclusion, the research of the anti-plane steady-state response to the cavity in the strip-shaped medium is of theoretical and engineering significance.
Effective grain orientation mapping of complex and locally anisotropic media for improved imaging in ultrasonic non-destructive testing
Published in Inverse Problems in Science and Engineering, 2020
K. M. M. Tant, E. Galetti, A. J. Mulholland, A. Curtis, A. Gachagan
In many countries, infrastructure is ageing and cannot be replaced due to global financial pressures. Industry is therefore presented with the challenging problem of safely maintaining their infrastructure and extending its life span. Ultrasonic non-destructive testing (NDT) involves the transmission of mechanical waves through industrial components to facilitate the detection of interior damage and offers an economically and environmentally desirable solution to this challenge. Networks of ultrasonic transducers, typically arranged in linear arrays, are deployed to carry out these inspections, resulting in large volumes of often noisy data. This data can be acquired using the Full Matrix Capture (FMC) technique [1], where each array element fires sequentially whilst all of the array elements record the reflected data simultaneously, thus maximizing the information extracted from a single array position. Using mathematical algorithms to decipher the resulting data sets, an image of the component's interior can be constructed and, in scenarios where the component is composed of a homogeneous material, defects can be reliably detected and characterized [1,2]. However, when the material exhibits inhomogeneous and/or anisotropic behaviour, its inspection becomes challenging [3–5]: the ultrasonic wave paths are distorted and their expected arrival times (on which many existing imaging algorithms are based) are usually no longer reliable.