SAFT Performance in Ultrasonic Inspection of Coarse Grained Metals
نویسنده
چکیده
Experience from the ultrasonic inspection of nuclear power plants has shown that large focused transducers are relatively effective in suppressing material structure noise. Operation of a large focused transducer can be thought of as integration (coherent summation) of individual beams reflected from the flaw and received by individual points at the transducer surface. Synthetic aperture focusing technique (SAFT), in its simplest version mimics an acoustic lens used for focusing ultrasonic beams at a desired point in the region of interest. Thus, SAFT should be able to suppress structure noise in the similar way as focused transducer does. This paper presents the results of investigation of SAFT algorithms applied for post-processing of ultrasonic data acquired in inspection of coarse grained metal specimens. The performance of SAFT in terms of its spatial resolution and grain noise suppression is studied. The evaluation is made based on the experimental data obtained from the ultrasonic inspection of test specimens with artificial defects (side drilled holes). SAFT algorithms for both contact and immersion mode are reviewed and experimentally verified.
منابع مشابه
Synthetic aperture focusing techniques for ultrasonic imaging of solid objects
Synthetic aperture focusing technique (SAFT) has been used in non-destructive testing mainly in its simplest form that mimics acoustic lenses used for focusing ultrasonic beams at a point of a solid object or structure. This paper presents a review of SAFT algorithms applied for post-processing of ultrasonic data acquired in non-destructive inspection of metals. The performance of SAFT in terms...
متن کاملLow Frequency-saft Inspection Methodology for Coarse-grained Steel Rail Components (manganese Steel Frogs)
In the rail industry, sections of high strength Manganese steel are employed at critical locations in railroad networks. Ultrasonic inspections of Manganese steel microstructures are difficult to inspect with conventional means, as the propagation medium is highly attenuative, coarse-grained, anisotropic and nonhomogeneous in nature. Current in-service inspection methods are ineffective while p...
متن کامل3D-SAFT Ultrasonic Inspection Equipment “MatrixeyeTM”
3D ultrasonic inspection equipment “Matrixeye” can visualize defects as 3D image with good resolution by the 3D SAFT (Synthetic Aperture Focusing Technique) imaging method. High-speed 3D SAFT imaging process can be achieved by the developed parallel signal process of the ultrasonic echo data collected by a linear or a matrix-array ultrasonic probe. It has the following features. •3D image with ...
متن کاملUltrasonic Imaging of Concrete by Synthetic Aperture Focusing Technique Based on Hilbert-Huang Transform of Time Domain Data
For non-destructive evaluation (NDE) of concrete, efficient and accurate imaging techniques are needed for a reliable evaluation of safety and serviceability of structures. Imaging of concrete structures is considered a very challenging task since it is a non-homogeneous material. In this paper, the acoustic (stress wave) technique was applied by using Ultrasonics and Synthetic Aperture Focusin...
متن کاملRemote photoacoustic imaging for material inspection
We report on (to our knowledge) the first remote contactless photoacoustic imaging with short excitation pulses on semitransparent solid polymer samples for material inspection. In this work solid semitransparent samples are excited with pulses from a short pulse laser. The local absorption of the electromagnetic radiation leads to generation of broadband ultrasonic waves. Ultrasonic waves arri...
متن کامل