This paper reports research activities in the authors’ group to develop a novel non-destructive testing method using a microwave to quickly inspect the inner surface of a pipe. The method propagates a microwave inside a pipe to detect anomalies appearing the inner surface on the basis of the reflection of the microwave due to the anomalies. Because the method does not require probe scanning unlike conventional non-destructive testing methods such as eddy current testing, it can inspect a long pipe quit...
英字タイトル:
Development of a non-destructive testing method for a long-range inspection of the inner surface of a long pipe

This study proposes a technique that would enhance the sizing ability of remote field eddy c urrent testing. Numerical simulations are conducted in an axisymmetric configuration modelin g remote field inspection of ferromagnetic steam generator tube. The simulations confirm an abrupt change of measured signal, and the change depends on the depth of a defect measured....
英字タイトル:
Remote field eddy current testing with controlled current distributions

This study develops a computational algorithm to distinguish stress corrosion cracking and fatigue cracks from signals measured electromagne tic-nondestructively. The algorithm utilizes k-nearest neighbour method, and distinguishes the two types of crack on the basis of five-dimens ional features vector extracted from the signals. Experimental verification are performed using 82 specimens including 45 artificial stress corrosion cracking and 37 artificial fatigue cracks. The results demonstarts that the a...
英字タイトル:
Electromagnetic Nondestructive Approach to Distinguish Stress Corrosion Cracking and Fatigue Cracks

The epochal electromagnetic nondestructive detection method was proposed. In this method a permanent magnet is utilized to generate a static magnetic field and a coil with several hundred turns is used to detect the eddy currents induce d inside the ball bearings. In the present study the method is applied to observed and evaluate ball bearings contaminated extraneous substances. Experimental validations are carried out using a common ball bearing. A wound and the malf unction of bearings are well detected...
英字タイトル:
Electromagnetic Nondestructive Detection for Ball Bearings Contaminated Extraneous Substances

Electromagnetic acoustic resonance (EMAR) method is used for online evaluation of pipe-wall-thinning. In this study, the thickness of the specimens corroded under various conditions is evaluated by EMAR. The thickness is estimated applying the superposition of n th compression (SNC) method to the signals obtained from EMAR. The error of thickness evaluation is investigated in view of thinning shape and the roughness caused by corrosion. As a result, it is suggested that the shape on the order of mm does not...
英字タイトル:
Study of evaluation accuracy of pipe-wall-thinning using electromagnetic acoustic resonance

This study evaluated the applicability of high-frequency ultrasonic testing to the inspection of W-Cu bonded interface aiming at the development of a non-destructive testing technique for the inspection of the cooling channel of the divertor of a fusion reactor. Tungsten blocks measuring approximately 30×30×13 mm were bonded with oxygen-free copper blocks using a high temperature vacuum furnace with uniaxial pressure and the thickness of the oxygen-free copper blocks was reduced to 2.5 mm. Artificial groove...
英字タイトル:
Nondestructive inspection of W-Cu bonded interface using high frequency ultrasound