The purpose of this study is to establish a computational procedure to support the optimization of an EMAT configuration. In this study, computer simulations were performed to obtain the propagation behavior of ultrasonic waves generated by an EMAT and the signals received with an EMAT. The simulation results were compared with the corresponding experimental results to validate the simulation method. The simulation results reasonably matched the corresponding experimental results....
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FEM simulation with consideration of electromagnetic interaction for transmitting and receiving ultrasonic waves with an EMAT

In order to study the influence of welding condition on the detectability of flaws in Ni based alloy by UT, we lding conditions, such as heat input, magnetic stirring and weaving were changed. Flaws in small heat input we ld joints was difficult to be detected because of the presence of high noise. On the contrary, welded joints m ade with large heat input and weaving showed lower noise and EDM notches in these joints were easily detected....
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The Influence of Welding Condition on Flaw Detectability by Ultrasonic Test in Ni Based alloy welds.

In the ultrasonic testing (UT) for weld part of austenitic stainless, it is generally recognized that the UT inspection has difficulty due to dispersion, attenuation, and so on. And, in UT results even for defect-free area of austenitic weld metal, echoes originated from root, columnar structure and interface between weld metal and base metal are observed with some continual variation throughout weld line. UT simulation is a very useful technique for understanding the phenomena in the ultrasonic wave ...
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Simulation of UT signal for columnar structure of weld metal of stainless steel piping

This paper presents an application of numerical simulation for ultrasonic guided wave in piping with elbow. A displacement field of torsion al guided waves in elbow and piping beyond elbow was computed using three-dimensional finite element models. We tried to utilize the predic ted displacement field to optimize the measurement condition or estimation of defect detectability. Experimental validation was carried our using artificial defects in elbow and beyond elbow region. Good agreement was obtained bet...
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Optimum measurements for pipe wall thinning in an elbow using torsional guided waves

Abstract Ultrasonic guided waves have been widely applied to the long-range inspection of straight piping. Guided waves have many wave modes with different sound velocity. So, ultrasonic testing beyond welds and elbows is very difficult to interpret testing data. This paper reports the simulation and visualization of guided wave propagation via a large-scale 3D FEM code, which has over one billion elements and parallel computing system. The prediction of torsional guided wave propagation and reflected ...
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Numerical simulation of torsional-mode guided wave inspection beyond elbows

Health monitoring of piping is one of the important issues to maintain its integrity.The guided wave monitoring is one of the promising methods r the health monitoring of piping．In this report，the optimum conditions of the guided wave method for both the flow-accelerated corrosion (FAC) and erosion of liquid droplet impingement (LDI) at around the elbow part of the piping were proposed and evaluated．The reason of the optimum con ditions was first explained and the experimental verifications were shown．Nume...
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On optimum detections of both LDI and FAC on an elbow part of piping by guided waves

In nuclear power plants, surface treatment including the shot peening is carried out after welding for the prevention of stress corrosion cracking. In this research, the authors developed evaluation systems of the persistence of compressive residual stresses due to shot peening based on the Idealized Explicit FEM which can conduct large-scale non-linear structure analyses in realistic computing time. The developed evaluation system was applied to the analysis of the compressive residual stress due to sho...
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Study of behaver to relieve residual stress at the time of the shot peening

It is well known that volumetric inspection by ultrasonic testing for cast austenitic stainless steel (CASS) piping, which is extensively used in primary loop of Japanese pressurized water reactors (PWR), is challenging due to unexpected beam skewing, dispersion and attenuation by its coarse and anisotropic crystal structures resulted from manufacturing process. The miss or false calling of the flaws and the deterioration of sizing performance are of great concerns in the ultrasonic testing for the ma...
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Simulation of Ultrasonic Wave Propagation in Cast Austenitic Stainless Steel Piping

An ultrasonic phased array technique has many advantages over conventional ultrasonic testing method. The phased array will eventually replace conventional ultrasonic NDT methods. However, the transition to phased array has several challenges. In this paper, phased array and conventional ultrasonic angle beam technique were compared under the aspect of weld testing. The detection and length sizing results of both methods for carbon steel butt welds were equivalent. Keywords: Phased array, Ultrasonic Test...
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Optimization of testing conditions for phased ultrasonic UT of welds

Abstract Ultrasonic testing (UT) is the most appropriate non-destructive testing because of capabilities for detection and depth sizing of flaw. But it is generally said that the flaw detection in austenitic weld is difficult because of dispersion and attenuation of the ultrasonic wave.UT simulation is a very useful technique for understanding the phenomena in the propagation of ultrasonic wave and for evaluating the UT results.On UT simulation for weld used austenitic welding material, modeling of co...
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UT simulation of dissimilar metal weld joint utilizing solidification simulation technique