This paper proposes a new flaw inspection technique by use of hysteresis heating and an infrared imaging device. If a periodical magnetic field is applied to a ferromagnetic material, it is heated by iron loss due to the m agnetic hysteresis as well as the Joule heat due to the eddy current. When the frequency of the magnetic field is not high and the magnetic permeability is large, the hysteresis heating is dominant, which enables us to uni formly heat a larger part of the specimen up to the deep region. ...
英字タイトル:
Visualization of Surface Defects of Steel Using Iron Loss And Infrared Thermography

Piezoelectric thin film has been used to visualize back surface defects in plates. When the plate with a back surface defect is deformed, the resultant strain distribution in the front surface reflects the shape of the de fect. Such surface strain distribution can be measured by scanning the electrostatic voltmeter over the piezoelectric film mounted on the front surface. In view of significant troubles of nuclear power plants due to defec t in pipes such as cracks and wastages, new nondestructive techniqu...
英字タイトル:
Measurement and Simulation of Detection of Defects on Inner Wallof Cylindrical Pipe by Piezoelectric High-polymer Film.

In order to detect back surface defects in a plate, the surface strain distribution is visualized by use of piezoelectric thin film. When the plate with a back surfa ce defect is deformed, the resultant strain distribution in the front surface reflects the defect. Such surface strain distribution can be obtained from the electric potential distribution on the piezoelectric film mounted on the front surface. The purpose of this paper is to detect the defects by measuring the electric potential distribution...
英字タイトル:
Monitor of searching damage with polymer piezoelectric high-polymer film

This study attempt to detect cracks in austenitic stainless steel by Magnetic Flux Leakage Technique with a high sensitive magnetic sensor. If a specimen is subjected to the stress, the magnetic properties change or the martensite phase is formed due to the plastic deformation or the stress induced phase transformation.. When the generated phase is martensite, this local change of magnetic property can be detected by measuring the Magnetic Flux Leakage with a sensitiv e magnetic sensor. In order to verify ...
英字タイトル:
Detection of Crack in Austenitic Stainless Steel with High Sensitive Magnetic Sensor

In this paper, we propose new inverse analysis method for reconstruction of magnetic permeability distribution using 2D magnetostatic analysis with Genetic Algorithm. We use Finite Element Method for 2D magnetostatic analysis, where the array of material number of each element is considered as genetic code. First, we produce genetic codes, i.e., individuals, randomly. We perform the FEM analysis to obtain the distribution of magnetic flux density near the specimen surface with respect to each individual. ...
英字タイトル:
Study on Inverse Analysis Method for Reconstruction of Magnetic Permeability Distributionusing 2D Magnetostatic Analysis with GA