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Keiko OTA, Yoshinobu TANIGAWA, Ryuusuke KAWAMURA
Article type: Article
Session ID: 3642
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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In the present article, we deal with a plane axisymmetric thermo elastic problem of a cylindrically anisotropic, inhomogeneous hollow circular plate, analytically. We assume that the material properties such as the Young's moduli, the coefficients of linear thermal expansion, and the thermal conductivities are independently varied in a form of power with radial coordinate γ, and that they also have cylindrically anisotropic properties. We formulate the equation of heat conduction in a steady state and the displacement equation of equilibrium for the hollow circular plate under a plane axisymmetric condition. Thereafter we derive analytical solutions of temperature change, displacement and stress components for the hollow circular plate which is subject to uniform heat supply at inner and outer boundary surfaces. We carry out numerical calculation and discuss the effect of interaction between material anisotropy and material inhomogeneity on the mechanical behavior of the hollow circular plate.
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[in Japanese], [in Japanese], [in Japanese], [in Japanese], [in Japane ...
Article type: Article
Session ID: 3643
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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In the present paper, we have dealt with a theoretical treatment of magnetothermoelastic problem in a conducting circular plate subjected to sinusoidal time variation of uniform magnetic flux in the thickness direction. We have derived temperature change in the plate due to eddy current loss and Lorentz force induced by interaction between eddy current and magnetic flux. We have ever formulated quasi-static solutions of displacement and stress subject to temperature change and Lorentz force under the plane axisymmetric condition. Since the frequency in Lorentz force is higher than that in temperature change, it is expected that the circular plate exhibits dynamic behavior. Therefore, considering inertia term in basic equation we formulate dynamic solutions of displacement and stress in this article. Carrying out numerical calculation, we discuss the effect of inertia term on magnetothermoelastic behavior in the plate.
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Yoshihiro OOTAO, Yoshinobu TANIGAWA, Akira TAKANO
Article type: Article
Session ID: 3644
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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This paper is concerned with the theoretical treatment of thermoelastic problem involving a laminated composite strip with an interlayer of functionally graded material. The thermal and thermoelastic constants of the interlayer are assumed to vary exponentially in the thickness direction. We obtain the exact solution for the two-dimensional temperature change, and thermal stresses of a strip under the state of plane strain. Some numerical results for the temperature change, the displacement and the stress distributions are shown.
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Hayato HIRATA, Hisao HASEGAWA
Article type: Article
Session ID: 3645
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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In a previous paper, a method of solution has presented for the stress concentration problem of an elastic infinite plate with a circular rigid inclusion under harmonic vibration loads. It was assumed that the vibration loads act at two points symmetrically located to the inclusion. In this paper we assume that a vibration load act at a point in an infinite elastic plate with a rigid circular inclusion, under plane strain conditions. A fundamental solution of the two dimensional elastodynamics for harmonandic vibration problems is applied, as similar to the previous paper. Displacements of the inclusion and stress distributions around the inclusion are investigated.
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Ryo SHIBUYA, Hisao HASEGAWA
Article type: Article
Session ID: 3646
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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This paper investigates on the elastodynamic problem of a circular thick walled cylinder subjected to harmonic vaibrational pressures on the inner surface, under a plane strain condition. A body force distribution method of solution is presented for the problem by applying fundamental solutions for harmonic vibrational loads in elasticity. The results are compared with exact solutions.
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Masahiro HIGUCHI, Yoshinobu TANIGAWA, Ryuusuke KAWAMURA
Article type: Article
Session ID: 3647
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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In the present study, dynamic and quasi-static behaviors of magneto-thermo-elastic stresses and deformations in a conducting infinite plate subjected to an arbitrary variation of magnetic field are investigated. It is assumed that a time-varying magnetic field which is defined by an arbitrary function of time acts on both side surfaces of the infinite plate in the direction parallel to its surfaces. Fundamental equations of one-dimensional electromagnetic, temperature and elastic fields are formulated. Then, solutions of magnetic field, eddy current, temperature change and both dynamic and quasi-static solutions of stresses and deformations are analytically derived. The solutions of stresses are determined to be sums of thermal stress caused by eddy current loss and magnetic stress caused by Lorentz force. The dynamic and quasi-static behaviors of the stresses are examined by numerical calculations.
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Kazumi Watanabe
Article type: Article
Session ID: 3648
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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Scattering of SH-wave by a closed crack is discussed based on a non-uniform spring model with singular stiffness. Incident and scattering wave fields are separated exactly by the technique of the eigenfunction expansion. Both impulsive and time-harmonic waves are derived.
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Shuji EGAWA, Nao-Aki NODA, Yasunori TASHIRO, Kouji TAKEOUCHI, Masakazu ...
Article type: Article
Session ID: 3649
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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The large-scale cast steel products have been used in broad fields, such as industrial machine, power generation, construction, vessels, and automobiles. In chill casting of cast steel uneven cooling rates at different regions of the large-scale cast steel generate thermal stress, which cause solidification cracks. The process of solidification process is complex in nature and the simulation of such process is required in industries before it is actually undertaken. In this study, a three dimensional thermal elast-plastic stress analysis has been preformed by using finite element method in connection with three dimensional non-steady state heat transfer analysis, including interaction between the temperature and stress field. The results provide further understanding of the observed solidification crack failure for large-scale cast steel.
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Yoshihiro OOTAO, Yoshinobu TANIGAWA, Yoshinori DAIDO
Article type: Article
Session ID: 3650
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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This paper is concerned with the theoretical treatment of transient thermal stress problem involving an angle-ply laminated hollow cylinder due to uniformly distributed heating. The one-dimensional solution for the temperature change in a transient state, and thermoelastic response of an angle-ply laminated hollow cylinder is obtained herein. As an example, numerical calculations are carried out for a 2-layered angle-ply laminated hollow cylinder made of. Some numerical results for the temperature change, the displacement and the stress distributions in a transient state are shown.
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Naoki HAYASHI, Hisao HASEGAWA
Article type: Article
Session ID: 3651
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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A body force distribution method is presented for the torsion problem of a rigid circular cylinder embedded in an infinite elastic thick plate. Here we apply a new Green's function for torsion problems of an infinite elastic thick plate in order to consider the stress singularity. The stress distributions of the problem were investigated in a previous paper. This paper deals with the order of stress singularity at the bottom corner of the cylinder. Luco investigated the torsion problem of a rigid cylinder embedded in an elastic half space and showed λ=1/3 for the order of singularity.
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Sei UEDA, Hironori KONDO, Atsushi HATAGAKI
Article type: Article
Session ID: 3652
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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In this paper, the mixed-mode crack problem for a functionally graded piezoelectric material (FGPM) strip is considered. It is assumed that the electroelastic properties of the strip vary continuously along the thickness of the strip, and that the strip is under in-plane electric loading. The problem is formulated in terms of a system of singular integral equations. The stress and the electric displacement intensity factors, and the energy density factor are presented for various values of dimensionless parameters representing the crack size, the crack location, and the material nonhomogeneity.
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Shouetsu ITOU, Takahiro HONMA, Yasuaki NAKASHIMA
Article type: Article
Session ID: 3653
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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An experiment has been conducted to determine stress intensity factors for two parallel cracks in an epoxy plate bonded to an aluminum plate. The corresponding values are also calculated using the theoretical method. It has been known that the stress intensity factor is reduced as the lower crack approaches the interface.
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Masayoshi SHIMIZU, Takahito GOSHIMA, Sotomi ISHIHARA
Article type: Article
Session ID: 3654
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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In this study, three dimensional internal inclined crack growth behaviors due to repeated rolling thermoelastic contact were considered. In this analysis, crack is modeled as an internal inclined planar crack in a three dimensional half-space. Rolling contact is simulated as a long and narrow distributed load with both normal and shear components moving with constant velocity. The shapes of crack contour are calculated under various conditions, which change angle of inclined crack.
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Yoshio ARAI, Demitris KOURIS, Eiichiro TSUCHIDA, Tohru YAMAGUCHI
Article type: Article
Session ID: 3655
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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The problem of elastic interaction between a surface step and an edge dislocation parallel to the surface is considered. Utilizing the displacement potential approach, the plane strain problem is solved analytically. A force on the edge dislocation due to step self-stress is evaluated as well as the one due to free surface. A potential minimum locus exists around the surface step for an edge dislocation. The relative configuration of step and dislocation (stepped direction and burgers vector direction) control the locus.
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Kouhei MATSUMOTO, Fumihiro ASHIDA, Sei-ichiro SAKATA
Article type: Article
Session ID: 3656
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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This paper discusses a stress control problem in a layered composite disk consisting of a transversely isotropic structural layer onto which a number of piezoelectric layers of crystal class 6mm are perfectly bonded. It is considered that some electrodes are arranged concentrically on the upper surface of each piezoelectric layer. When an axisymmetric heating temperature acts on the bottom free surface, the maximum thermal stress induced in the structural layer is controlled by applying an appropriate voltage to each electrode. The voltages applied to electrodes are determined by optimization using the BFGS quasi-Newton method so that the maximum thermal stress in the structural layer is minimized subject to constraints on the stresses in the piezoelectric layers. Finally, numerical results obtained for a composite disk consisting of a transversely isotropic CFRP layer and a number of cadmium selenide layers of crystal class 6mm are shown in tables.
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Yoshihito OZAWA, Tokio KIKUCHI, Masayoshi WATANABE, Koichi YABUKI
Article type: Article
Session ID: 3657
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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In this study, the mechanical behavior of composite material system with ultra light weight is investigated in the atmospheric condition. The matrix resin of the composite is epoxy resin and its dispersion is glassy micro "Sirasu Balloon". The composite system developed is a kind of micro porous materials. From the experimental data of bending tests and impact tests, mechanical behavior of the composites was clarified, and the effects of material properties and configurations on the mechanical properties of the composite were discussed from the viewpoint of micro-mechanical study. A homogenization theory with multi-scale analytical method will be described for evaluation of the composite material system in environmental conditions.
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Sei-ichiro SAKATA, Fumihiro ASHIDA, Masaru ZAKO
Article type: Article
Session ID: 3658
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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This paper discusses accuracy of estimated gradient and Hessian components in approximate optimization. Several flexible approximate optimization methods can estimate gradient and Hessian components of an estimated surface without using finite difference, and it will be available in approximate optimization process using a gradient-based optimization method. Since its accuracy affects an estimated result of optimum solution or convexity, accuracy of estimations by those flexible methods should be investigated. In this study, accuracy of gradient and Hessian estimation by Kriging method is investigated. At first, in this paper, a formulation for gradient and Hessian estimations by Kriging method is described. Next, accuracy of those estimations is discussed with numerical results.
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Takuya MORIMOTO, Yoshinobu TANIGAWA
Article type: Article
Session ID: 3659
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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We study the postbuckling behavior of inhomogeneous thin plates subjected to in-plane compression. We focus on the effect of the inhomogeneity of Poisson's ratio on the nonlinear behavior of the plate in which the buckling modes is kept the translational symmetry. First we discuss the symmetry of the stress function in order to clarify whether the governing equations are solvable as a linear problem. Next we proceed to the nonlinear analysis and derive the postbuckling deflection, its amplitude and resultant forces in explicit forms. Under given concrete expressions of the elastic stiffness, the effects of the material inhomogeneity and orthotropy on the postbuckling deflection, its amplitude and resultant forces are examined.
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Senji IMAMURA, Yuichi SAITO, Kenji MIYATA
Article type: Article
Session ID: 3660
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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An intelligent universal test machine can measure the relationships between stress and time, and strain and time. The tensile test of the indistinguishable yield point of S45C was carried out using the intelligent universal test machine. The relationship between stress and time showed three different types of behavior, types A, B and C, depending on the elevated tensile speed. For type A, no clear elasticity-plasticity transition point (E-P point) is observed. For type B, an E-P point is clearly observed. For type C, an E-P point is also observed, but elastic behavior appears in the plastic region. The results of the experiment were analyzed by considering the relationship between strain and time in the plastic region, which is shown to be linear. We conclude that the slope of the experimentally determined equation is dependent on the material, and the graft is dependent on the elevated tensile speed.
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Yasuyuki KATO, Youichirou YAMAMURA, Kazunari YABE
Article type: Article
Session ID: 3661
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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Generally, as for the material of catheter, soft characteristic is necessary not so as to damage vascular wall etc. On the other hand, a responsibility and enough rigidity are also required for the surgical operations such as myocardial or cerebral infarction. The purpose of this study is to investigate physical property of the catheter, which made of soft nylon resin and is reinforced stainless braid. In a previous report, combined tension and torsion tests have been carried out to investigate visco-elastic response under multi-axial loading, and we have been discussed the effect of braid's angle. In this paper, we investigate the stress relaxation under two-stage step strain with respect to tension and torsion. In addition, we try to formulate the numerical model for visco-elastic response based on these experimental results.
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Mitsuo KOBAYASHI, Yoshihiro HIRAKAWA, Katsumi FUKUDA, Michihiko TANAKA ...
Article type: Article
Session ID: 3662
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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One of the design methods for closing the end of a pressure cylinder is to screw down a screw plug on the threaded end of the cylinder. In this case, these is the problem of stress concentration in the threaded end of the pressure cylinder. To solve the problem, it is necessary to know accurately the load distribution on the threaded end of the cylinder. To find the load distribution on the threaded end of the pressure cylinder engaged with the screw plug, the following experiments are carried out. Applying the tensile load between the plug and the pressure cylinder and regarding the situation above as equivalent to the situation in which the internal pressure is applied, the load distribution is measured with the strain gauge. The influence of material of engaged thread on the load distribution on the threaded end of pressure cylinder is presented and an expansion of design manual is discussed.
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Masakazu UCHINO, Yasutaka SAGAWA, Kouzou ONOUE
Article type: Article
Session ID: 3901
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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Strain measurement of concrete test pieces was usually performed by using a strain gauge and an embedded strain gauge. But recently, a non-destructive full-field measurement method is strongly required for measurement of complex structures and maintenance management system for structures. A digital image correlation method is a very simply measurement method for the surface deformation using only digital images are taken by a CCD camera. In this study, we will perform the strain measurement of concrete test pieces by using the digital image correlation method to investigate the validity of the optical measurement method.
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Yasuyuki MORITA, Masakazu UCHINO, Kazuo ARAKAWA, Mitsugu TODO
Article type: Article
Session ID: 3902
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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This study aims at clarifying dental occlusion functions of periodontium. Then, digital image correlation method was applied to observe the deformation of the periodontium. The periodontium consists of a molar, periodontal ligament, and alveolar bone. The experimental result showed that the periodontal ligament played an important role in the dental occlusion functions.
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Kensaku SHINOHARA, Tashiyuki TORII, Kouichi NAMBA, Kenichi SHIMIZU
Article type: Article
Session ID: 3903
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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A digital image correlation method was used for measurement of COD distribution along the crack using slip pattern around fatigue cracks. In this measurement, selecting a subset in high contrast region was important for correct search. In addition, location of subsets near the crack and distance between subsets crossing the crack were found to have less effect on the COD distributions. Based on the COD distributions, stress intensity factor range ΔK_<est> was evaluated and used for estimating fatigue crack propagation rate.
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Kenichi SAKAUE, Satoru YONEYAMA, Gan SATO, Masahisa TAKASHI
Article type: Article
Session ID: 3904
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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Digital image correlation is applied to measure displacement and strain fields around a crack tip in a polycarbonate plate specimen. From the displacement data obtained by digital image correlation, stress intensity factor and J-integral on arbitrary paths are calculated. The measurement results show that localized strain region appears at a crack tip before crack initiation and that the strain region propagates forward of the crack tip. After formation of the strain region, the stress intensity factor of the crack increases remarkably and J-integral depends on integral paths due to formation and propagation of plastic zone.
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Satoru YONEYAMA, Akikazu KITAGAWA, Setsuo IWATA, Kazuhiko TANI, Hisao ...
Article type: Article
Session ID: 3905
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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This paper demonstrates bridge deflection measurement using digital image correlation technique during bridge load testing. A bridge is loaded by a heavy cargo truck on the bridge road. Then, the deflection distribution is measured by digital image correlation. The applicability of digital image correlation to bridge deflection measurement is investigated by comparing the results obtained by digital image correlation with those obtained by displacement transducers. The effect of random pattern on an object surface is also investigated by measuring with and without random pattern. Results show that the deflection distributions of the bridge obtained by digital image correlation agree well with those obtained by displacement transducers when random pattern is attached on the bridge surface. In addition, it is found that deflections can be measured even if artificial random pattern is not applied to the surface of bridge girders. It is emphasized that noncontact displacement measurement is possible by simple and easy procedure with digital image correlation for the structural evaluation of infrastructures.
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Akira KATO, Takahito MORIUCHI, Rie FUNATANI
Article type: Article
Session ID: 3906
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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We investigated a method to measure displacement distribution in the whole view field of a CCD camera using digital image correlation (DIC) technique. This method intends to measure displacement field on a surface by comparing two images before and after deformation taken with a CCD camera. In this method, accuracy of the search method of the corresponding points on the two images influences largely on the accuracy of the measured result. In this paper, we investigated an interpolation method to estimate gray level using neighboring pixel data and gray level correction method for template matching with accuracy less than one pixel.
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Masakazu UCHINO
Article type: Article
Session ID: 3907
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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Naoki MIZUHARA, Satoru YONEYAMA, Hisao KIKUTA
Article type: Article
Session ID: 3908
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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This paper describes a new simultaneous phase stepping method for moire interferometry. Conventional phase-stepping methods are widely accepted but the measured data are vulnerable to disturbances such as air fluctuations, temperature changes, vibrations and so on during the interferogram recording. To overcome this, a unique camera having a micro-retarder array on a CCD is used for observing interferograms. The specific structure makes it possible to calculate polarization states. Using this camera in a moire interferometer, the distribution of in-plane displacements is obtainable from a single image.
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Masahiro SUETSUGU, Hiroya NAGATA, Koji SHIMIZU
Article type: Article
Session ID: 3909
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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Dynamic fracture behavior caused by the out-of plane loading is evaluated by the method of caustics. Out-of plane displacement is measured by the C.G.S. method under static loading and it is in good agreement with theoretical one. Diameter of caustic pattern formed by the out-of plane loaded plate is compared with that one calculated by the theoretically induced formula. Dynamic fracture testing apparatus is assembled with the ultrahigh-speed camera, and caustic pattern under dynamic loading is obtained. Moreover, dynamic fracture characteristics of PMMA plate are discussed.
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Shinichi SUZUKI, Tomotaka MIYASITA
Article type: Article
Session ID: 3910
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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Stress intensity factor of bifurcated notches are obtained by measuring opening displacement with Moire interfrometry. The bifurcation angle is 13.5 degrees that is the angle of bifurcation of fast propagating cracks. The measurement results say that the stress intensity factor of a bifurcated notch has the same value as that of the single notch whose length is the same as that of the bifurcated notch. This is caused by the small bifurcation angle.
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Syuutei Sasaki, Tsutomu Ezumi
Article type: Article
Session ID: 3911
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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The double column made of dissimilar materials about the experimental analysis is reported a little. The author experimented about a double column with the dissimilar material o is used in various fields. When the boundary of this double column is dynamically seen, a discontinuous joint field side is a singularity point with a very big stress. The crack occurs easily in phase boundary of the different kind material for that reason. The stress analysis of vicinity at the edge of the crack to which destruction is expected to evaluate this in strength is necessary. The stress intensity factor is effective to clarify the behavior of the states when the crack of a double column exists in the phase boundary at the vicinity of the crack. This research is a photoelasticity method and due to the coustics method with stress freezing method and was got the good result.
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Yuuki IGARASHI, Haruo NAKAMURA
Article type: Article
Session ID: 3912
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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Hirotsugu KOBAYASHI, Hiroshi KATO, Kensuke KAGEYAMA
Article type: Article
Session ID: 3913
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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This paper describes ultrasonic evaluation of initiation and propagation processes of fine cracks at the bonding interface of Sn alloy solder joints under repeated loading. The specimens were subjected to acoustic microscopy to obtain the acoustic images at bonding interface of the solder joints at required numbers of fatigue cycles during shear fatigue testing. The brightness change was observed in the bonded area. After fatigue failure, the fracture surface of SEM image was compared with the acoustic image. In the part of the brightness change in the acoustic image, many fine cracks were observed in the SEM image. The number of fine cracks on the fracture surface was greater at periphery than those inside the bonded region, and increased with increasing number of the fatigue cycles. It was found that the effective bonding area at the final failure was almost the same for specimens of different fatigue lives.
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Tetsuo Kumazawa, Noboru Nakayama, Nobukaya Ito
Article type: Article
Session ID: 3914
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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An electromotive force in deformation of Pb free solder joint was generated and measured successfully by a thermo-couple. The method using the thermo-couple proposed in this study is combined with a conventional testing machine. Using the testing machine, both the load-deformation diagram and electromotive force were obtained at the same time. The peak value of electromotive force in tension and shearing increased linearly as the deformation speed increased. The electromotive force in shearing was smaller than the value in tension. This small electromotive force could be related to the small strain energy and results in weakness in shearing of solder joint.
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Takashi YOKOYAMA, Kenji NAKAI, Tomoya IKEDA
Article type: Article
Session ID: 3915
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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Takashi YOKOYAMA, Kenji NAKAI, Takafumi ODAMURA
Article type: Article
Session ID: 3916
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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Hisayoshi SAITO, Sigeru KUROSAKI
Article type: Article
Session ID: 3917
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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Piezoelectric film is noticed as a sensor for the monitoring recently. Because, amplifier and power are unnecessarily. In this study, the strain measurement which uses the piezo cable a built-in piezoelectric film was tried. In the experiment, in order to know the tensile characteristic of a piezo cable simple substance first, the static tensile examination was performed. And cyclic tensile load applied to the piezo cable, various influences which it causes to output voltage were inspected. Especially, it changed cable length, load frequency, load amplitude. As a result, I understood that the output voltage of a piezo cable increased in proportion to the displacement amplitude. Therefore, the possibility was discovered where it can utilize the piezo cable as the strain sensor.
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Takuya OGAWA, Masanobu KUBOTA, Chu SAKAE, Yoshiyuki KONDO
Article type: Article
Session ID: 3918
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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Estimation of the applied stress to the fractured component is important in failure analysis in fatigue fracture accident in order to determine the cause of fracture and to prevent another failure. The estimation using striation spacing achieved success in the very limited range of ΔK. The objective of this study is development of estimation methods, which are applicable in the wide range of ΔK from crack propagation threshold to striation formation. Electric impedance method and fracture surface hardness one were examined. Electric impedance of fatigue fracture surface was measured within the plastic deformation layer by using high frequency current. The impedance increased with increase of the K value. Micro Vickers hardness was measured on the fatigue fracture surface. The hardness was defined as the area of indentation mark to reduce the effect of the roughness of fracture surface. The hardness increased with increase of the K value.
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Kazuo ARAKAWA, Toshio MADA, Haruo KOMATSU, Tetsuo SHIMIZU, Masanori SA ...
Article type: Article
Session ID: 3919
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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The normal impact between a golf ball and a rigid steel target was studied using a high-speed video camera. Video images recorded before and after impact were used to determine the inbound and rebound ball velocities. The images during impact were also employed to analyze the deformation of the ball. Displacement at the center of the ball was measured during impact to determine the instantaneous ball velocity and acceleration. Reaction force was evaluated by the product between the mass and acceleration of the ball. It was found that the force increased linearly with the inbound velocity.
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Kiyotaka SAKINO, Shingo YOKOO
Article type: Article
Session ID: 3920
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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In order to evaluate the strain rate sensitivity of dynamic flow stress of aluminum alloy at very high strain rates, constant strain rate tests and strain rate reduction tests are conducted for 7075-T6 in the strain rate range from about 1×10^3s^<-1> to 3×10^4s^<-1>. The flow stress increases steeply above about 2×10^4s^<-1>. The behavior is interpreted on the basis of a simplified model which can represent a transition in the rate controlling mechanism of dislocation motion from a thermally activated process to a viscous drag.
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Hiroshi KATO, [in Japanese], [in Japanese], Hiroko SAITO, Kensuke KAGE ...
Article type: Article
Session ID: 3921
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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The longitudinal ultrasonic wave was irradiated on a specimen surface in water at an angle of 30 deg to generate the surface acoustic wave (SAW) on the surface. The intensity of SAW was measured under different conditions, and it was found that the intensity of SAW decreased during propagating on the specimen surface greatly compared to the ultrasonic wave traveling in the waver. Then two SAWs were propagated on the plate surface in the opposite direction and were overlapped to generate the standing interference wave. Small alumina particles were scattered in a region where the standing interference wave was generated to distribute the particles following the standing wave. However, there was no formation of the sinusoidal distribution of the particles.
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Ryosuke MATSUZAKI, Keita WASHIZU, Akira TODOROKI
Article type: Article
Session ID: 3922
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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Measurement of strain of tires in-service is effective to improve reliability of tires and ABS system. Since conventional strain gages have high stiffness and require lead wires, the conventional strain gages are cumbersome for the strain measurement of the tires. The backgrounds require a new low cost wireless sensor for tires. In the present study, a new flexible patch-type strain sensor utilizing electric capacitance change is proposed and analytically investigated. The sensor is made from flexible polyimid substrates and flexible epoxy resin whose elogation is 150%. The sensor has quite low stiffness and applicability to large deformation. The capacitance change of the sensor due to applied strain is investigated using FEM analysis. As a result, the sensor is analytically proved to be effective for the strain monitoring of tires.
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Yoichiro HIWATASI, Ryota KAMATA, Haruo ENDOH, Tsutomu HOSHIMIYA
Article type: Article
Session ID: 3923
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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Heat affect zone in weldment of stainless steel was measured with the photothermal electrochemical (PE) detection scheme. "Heat affect zone" is the interface zone between steel plates generated in weldment. PE detection scheme was based on the accelerated chemical reaction caused by the absorption of laser light associated heat generation (photothermal phenomenon). For the specimens, a heat affect zone was prepared by arc welding method. The periodically modulated beam of an Ar^+ -ion laser is focused on the surface of a stainless steel plate, which is immersed in a 3.5% sodium chloride (NaCl) aqueous solution. A welded stainless steel plate was used both as a specimen and as an anode in electrochemical reaction. Nondestructive measurement of heat affect zone in weldment was carried out using the PE imaging with a X-Y scanning system controlled by a PC. PE amplitude images and signals were obtained at the similar spatial resolution. The PE amplitude signal intensity varied with the shape of heat affect zone in weldment.
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Hayato SUZUKI, Kensuke ICHINOSE, Kenji GOMI
Article type: Article
Session ID: 3924
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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This paper reports on a new technique for measuring of birefringence to obtain stress fields using laser photoelasticity. The technique of this report provides for the measurements of magnitude and the azimuth of the birefringence. In order to check the validity of the technique, birefringence of a 10[nm] waveplate and 79.1[nm] waveplate were examined. Good quantitative agreement was obtained between measured values and the theoretical calculations. The effectiveness of the new technique of this report was confirmed by experimental result.
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Shuichi ARIKAWA, Kensuke ICHINOSE, Kenji GOMI
Article type: Article
Session ID: 3925
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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On annealed carbon steel, the effect of a localized yield area on distribution of strain is observed by using electronic speckle pattern interferometry (ESPI). First, the decrease of the Young's modulus with yielding is examined by using ESPI. Next, on loaded specimen, distribution of strain is observed by using ESPI. This observation is done for the specimen that has a localized yield area and the specimen that does not have a localized yield area. As a result, these distributions of strain are different. For that reason, on annealed carbon steel, the effect of variation of the Young's modulus with yielding on distribution of strain is examined by using ESPI.
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Yuichi FUJITA, Hirohisa KIMACHI, Kaori SHIRAKIHARA, Takumi INAGAKI
Article type: Article
Session ID: 3926
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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It is very important to grasp the stress/strain states in micro scale area. In this study, Raman microspectroscopy was applied to the measurement of the components of stress/strain in the single crystal sapphire and polycrystalline alumina. First, the relationships of A_<1g> and E_g modes between the change of Raman shift and strain components were theoretically derived, based on Energy change under mechanical loading. In theses relationships, the all parameters necessary to determine the components of stress/strain were found, and the determination method of these parameters was shown. Next, in order to determine these parameters experimentally, four point bending tests of single crystal sapphire were conducted. In A_<1g> and E_g modes, the change of Raman shift was liner to the applied strain. Last, the stress measurement around the notch root in the single crystal sapphire was performed. The measured strains were good agreement with the FEM results. Therefore, the applicability of Raman micro spectroscopy to measurements of stress/strain in micro scale area was confirmed.
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Hironori TOHMYOH, Takuya IMAIZUMI, Masumi SAKA
Article type: Article
Session ID: 3945
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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Acoustic resonant spectroscopy technique for measuring the acoustic impedance, ultrasonic velocity and density of micron-scale polymer films is developed. The method observes the acoustic resonance between water, film and the tungsten plate at the frequency range of 20-70MHz, where the interface between the examined film and the plate is vacuum-sealed, and it enables us to characterize a low-density polyethylene film with low acoustic impedance of about 1.9MNm^<-3>s and a poly (vinyl chloride) film as thin as about 8μm.
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Yoshimasa TAKAHASHI, Hiroyuki HIRAKATA, Takayuki KITAMURA
Article type: Article
Session ID: 3946
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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A novel in situ TEM fracture testing method is developed to elucidate the mechanics dominating crack initiation at an interface edge in nano-structures. The testing method effectively utilizes the bending moment of a cantilever to cause a tensile stress to the interface of interest. The nano-scale cantilever specimens with interfaces are fabricated from a multi-layered material (Si/Cu/SiN) using FIB process technique. The validity of the testing method is demonstrated by conducting interfacial crack initiation experiments for the specimens with different size. For each specimen, the crack is initiated from the free-edge of interface between Si/Cu at a maximum load, P_c, and the specimen is instantly separated at the interface. Using the experimental results the stress fields along the Si/Cu interface at the crack initiation are analyzed for each specimen by finite element method. This reveals that the crack initiation of the Si/Cu interface is governed by the normal stress on the interface near the edge
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Harunori FURUTA, Shoji KAMIYA, Masaki OMIYA
Article type: Article
Session ID: 3947
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
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Interface adhesion energy between copper and polyimide films, which is used as flexible printed circuits, was evaluated. Contrary to the peel test commonly applied to such a case, interface crack-extension with less amount of plastic deformation was realized by a new technique. On the basis of experimental data, elastic-plastic finite element model was calculated to independently determine the amounts of plastic work and energy consumed to separate the interface during the crack extension process. Both the approaches of total energy balance and work given by nodal force and displacement at the crack tip agreed well and resulted in the same amount of the interface energy release rate.
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