The shape of a magnetic body was detected with measurement of the magnetic field distribution using the hall sensor. Test specimens with a step on the backside were measured and, the magnetic flux of the experiment was compared with the analysis. The experiment and the analysis showed a similar tendency, and differences in the thickness of the specimen were detected. But sensitivity of detection was not improved by using the magnetic lens. Results will the presented the experiment and the analysis in the case of different shape of the magnetic lens.

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The effect of magnetic fields on the stress intensity factors in soft ferromagnetic plates under uniaxial tension is investigated. Tension tests were conducted on nickel-iron soft magnetic materials with center-cracked plate specimen geometries in a 10 T cryocooler-cooled superconducting magnet at room temperature. Strain gages were used to evaluate the magnetic stress intensity factors. The existence of the magnetic field produces larger values of the stress intensity factor. This effect becomes more pronounced with increasing the magnetic susceptibility.

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The electron moire method has been considered as a method with significant potential applications in the microscopic analysis of materials. Fine gratings are being pursued to meet high resolution requirements in microscopic stress analysis. Currently, about 5,000 lines/mm of the grid (cross-lines) have been reported. In this study, a moire method of using a grid with a frequency of 10,000 lines/mm is introduced.

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We investigated a method to evaluate fatigue damage and estimate fatigue life using laser without contact. When a low carbon steel is loaded cyclically, slipbands appear on the specimen surface and thus the specimen surface changes with progress of fatigue damage. The present method intends to detect the surface change caused by fatigue observing pattern change of diffused light when a laser illuminates the specimen surface. In this study, we observed the pattern change of the diffused laser light during fatigue and investigated a method to evaluate fatigue damage and possibility for estimating fatigue life using this technique.

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The thermal residual strain at the internal position of the materials was measured nondestructively by neutron diffraction. The diffractometers, RESA at JAERI and Sirius at KEK were used. The three-layers joint materials of sintered hard alloy and normal metal made by Self-propagating High-temperature Synthesis and the S45C round bar hardened by induction heating were measured. The results obtained by the measurements are discussed precisely. The difference of the characteristic of the two diffractometers was also discussed.

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Pulse heating thermographic NDT was applied for corrosive material loss in steel plates used for shell of automobile bodies. Pulse heating by xenon flash lamp was applied to the surface of steel plate. Transient temperature distribution on the surface of steel plate was measured by the high speed infrared thermography. Artificial material loss defects (20% and 40% loss in thickness) introduced by electro-discharge machining were tested. It was found that defects were detected as localized high temperature areas appeared in the short time duration after the pulse heating. The present technique was also applied to the artificial corrosive material loss in steel plates. Artificial corrosive material losses were introduced to the steel plates by alternately exposing the plates to salt water and air. It was found that the location and size of the material losses were determined by the thermal images taken after pulse heating, and depth of the defects can be estimated by the sequential thermal images.

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This paper explains the joint reliability of the electronics packaging which uses lead-free solder. The basic physical properties of the lead-free solder materials as the Sn-Ag-Cu and the Sn-Zn are investigated and compared first. And, the joint reliability of the TSOP lead-type component was examined as one of electronic components with a short fatigue life.

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The tendency of portable telephone and miniaturization of electronic equipment that it is supposed in book-size personal computer, etc., portable type is remarkable in recent years. The impact breakdown in the soldered joints division by the falling surfaces with it as a new problem. However, the elucidation of the effect of the whole package of the behavior on soldered joints divisions is insufficient to the destruction, and it is necessary to clarify the behavior, when the impact breakdown in the soldered joints division is evaluated. Then, it is necessary to clarify the behavior, when the impact breakdown in the soldered joints division is evaluated.

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Resonance ultrasound spectroscopy (RUS) was studied with the purpose of developing an on-line inspection technique of disbonding in the chip scale package (CSP) assemblies an important miniature semiconductor package consisting of silicon monocrystal, ceramic base, and plastic thin layer between them. We put the CSP on three pins, two pinducers and one supporting pin, and measured the resonance frequencies by driving one pinducer with sinusoidal waves and detecting the oscillation amplitude through the other pinducer. Only the CSP mass (^∿0.4g) contributed to the ultrasonic-vibration transmission and reception, and neither coupling agent nor external load was necessary. The resonance frequencies decrease with disbonding, depending on the antinodes relative to the damage location.

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This study is concerned with theoretical development for thermally induced vibration problem of an inho-mogeneous beam. We suppose that thermal and mechanical material properties in beam are given as power function in term of transverse coordinate z. Firstly, we have developed one-dimensional transient heat conduction problem of an inhomogeneous beam due to cyclic heat supply. Then, we have developed thermally induced vibration problem of an inhomogeneous beam clamped at one edge and free at opposite edge. Next, we have carried out numerical calculations and have discussed about effects of both cyclic temperature fluctuation and nonhomogeneity of material properties on thermal displacements, thermal stresses and resonance characteristics.

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This paper examines the problem of thermal cracking under a transient temperature field in a ceramic/metal functionally graded plate. When the functionally graded plate is cooled from high temperature, it could be observed that curved or stright multiple cracks occur on the ceramic surface. In addition, those multiple cracks influence each other and form complex arrays. To investigate mutual effect among multiple cracks, crack paths are simulated using finite element method. Transient thermal stress field and crack growth are treated as a linear quasi-static thermoelastic problem for a plane strain state.

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The object of this paper is to study the numerical treatment of wave propagation behavior of a piezoelectric hollow circular cylinder under axisymmetric thermal, electric, and mechanical lordings. The general dynamic equations are based on the first-order partial differential equations with stresses, particle velocity, electric displacement, and electric field intensity as the dependent variables. This system of equations is analyzed by the method of characteristics. A numerical procedure, which integrates the characteristic equations along characteristics via a step-by-step integration technique, is established. Graphical displays are utilized to present the influences of piezothermoelastic constants on the wave profiles.

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Two Green functions for a radially inhomogeneous elastic solid with linear velocity variation are obtained exactly. Both impulsive and time-harmonic point sources are assumed. Wave front shapes and rays for transient waves and particle motions for the time-harmonic response are illustrated. Non-wave nature in the time-harmonic Green function is found for the case of constant velocity gradient.

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