Showing papers by "Tetsuya Uchimoto published in 2006"
TL;DR: In this article, the structural variation in a series of cast iron samples was non-destructively characterized by means of sets of magnetic minor hysteresis loops, without magnetic saturation of the samples.
Abstract: Structural variation in a series of cast iron samples was non-destructively characterized by means of sets of magnetic minor hysteresis loops. The flat samples were magnetized by an attached yoke, and reliable parameters were obtained from the series of minor loops, without magnetic saturation of the samples. It was found, that some magnetic quantities, well known to be closely connected to the samples' structure variation, especially relative coercivity and remanent induction, could be distinguished more sensitively from minor loops, than from the major one.
9 citations
TL;DR: The possibility of using leaky Rayleigh waves as a nondestructive tool for the evaluation of CVD diamond coating layer is explored experimentally and a novel signal analysis approach is proposed, namely the "time trace angular scan (TTAS)" image.
7 citations
TL;DR: In this paper, the propagation characteristics of the back-reflected Rayleigh surface wave in chemical vapor deposit (CVD) diamond coated specimens were investigated experimentally using the ultrasonic backward radiation measurement.
Abstract: The propagation characteristics of the back-reflected Rayleigh surface wave in chemical vapor deposit (CVD) diamond coated specimens were investigated experimentally using the ultrasonic backward radiation measurement. The deliberated delaminations produced between the coating layer and the substrate decreased Rayleigh surface wave velocity. This initial experimental result obtained in the present study demonstrates the high potential of the backward radiated ultrasound as a tool for nondestructive evaluation of very thin CVD diamond coating layer.
5 citations
TL;DR: In this paper, an eddy current testing (ECT) system with multi-coil type probes is applied to size up cracks fabricated on austenite stainless plates, which consist of transmit-receive type sensors as elements to classify crack directions, working as two scan direction modes simultaneously.
Abstract: An eddy current testing (ECT) system with multi‐coil type probes is applied to size up cracks fabricated on austenite stainless plates. We have developed muti‐channel ECT system to produce data as digital images. The probes consist of transmit‐receive type sensors as elements to classify crack directions, working as two scan direction modes simultaneously. Template matching applied to the ECT images determines regions of interest in sizing up cracks. Finite element based inversion sizes up the crack depth from the measured ECT signal. The present paper demonstrates this approach for fatigue crack and stress corrosion cracking.
4 citations
05 Jun 2006
TL;DR: In this article, a crack sizing method in eddy current testing (ECT) for austenite stainless steel plates is proposed, where the image and finite element analyses for the ECT response maps estimate size of surface breaking and crack depth, respectively.
Abstract: This paper proposes a crack sizing method in eddy current testing (ECT) for austenite stainless steel plates. The image and finite element analyses for the ECT response maps estimate size of surface breaking and crack depth, respectively. At first, template matching identifies surface breaking in fragments. Second, measuring the length of fragment gives a quasi-3D region for sizing crack depth. Third, the crack is reconstructed by iteration of fast finite element analysis. Finally, overlapping all evaluated cracks represents complicated-shape cracks. It is shown that size of stress corrosion cracking is efficiently estimated
1 citations
1 citations
TL;DR: In this article, the authors proposed the time trace angular scan (TTAS) method and the frequency spectrum angular scan method to help the interpretation of the back-scattered Rayleigh surface waves from the CVD diamond coating layer.
Abstract: To evaluate the adhesive property of chemical vapor deposit (CVD) diamond coating layer, back‐scattered Rayleigh surface wave method is applied. However, the interpretation of the back‐scattered Rayleigh surface signal is not easy. To take care of such a difficulty, we propose the time trace angular scan (TTAS) method and the frequency spectrum angular scan (FSAS) method to help the interpretation of the back‐scattered Rayleigh surface waves from the CVD diamond coating layer. Using the proposed signal interpretation tools, we evaluate the adhesive property of CVD diamond coating layer. In this paper, the concept of the TTAS and the FSAS methods and the initial experimental results are presented to demonstrate the effectiveness of the proposed approach.
TL;DR: In this article, fatigue cracks and SCC (Stress Corrosion Cracking) on a back surface were detected and the shape of cracks were evaluated using a surface wave generated by focusing angle beam ultrasound.
Abstract: Fatigue cracks and SCC (Stress Corrosion Cracking) on a back surface were detected, and the shape of cracks were evaluated using a surface wave generated by focusing angle beam ultrasound. Internal ultrasonic images showed a little shorter length than optical images. Cross section of the fatigue crack and internal distribution of complicated shaped SCC were estimated.