SOLID MECHANICS UNDER MAGNETIC FIELD
Eiji MATSUMOTO
Review Paper (Vol.5 No.1)
SOLID MECHANICS UNDER MAGNETIC FIELD |
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Eiji MATSUMOTO |
1 |
General Papers (Vol.5 No.1)
STRESS-STRAIN RESPONSE OF ROCK-FORMING MINERALS BY MOLECULAR DYNAMICS SIMULATION |
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Yong-Seok SEO, Yasuaki ICHIKAWA and Katsuyuki KAWAMURA |
13 |
SUITABLE SAMPLE AREA AND NUMBER OF DIVISIONS IN THE ESTIMATION OF THE MAXIMUM CRACK LENGTH BY EXTREME VALUE ANALYSIS |
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Takashi MATSUMURA and Masahiro ICHIKAWA |
21 |
STRUCTURE AND PROPERTIES OF IONOMERS BASED ON ETHYLENE-CO-METHACRYLIC ACID COPOLYMER (EMAA) |
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Xiangsheng ZENG, Hideki YAMANE, Masaoki TAKAHASHI and Toshiro MASUDA |
28 |
STRUCTURE AND PROPERTIES OF IONOMERS BASED ON ETHYLENE-CO-METHACRYLIC ACID COPOLYMER (EMAA) |
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XiangSheng ZENG, Hideki YAMANE, Masaoki TAKAHASHI and Toshiro MASUDA |
33 |
THERMAL STABILITY OF RF-SPUTTERED AMORPHOUS FILMS IN COMPARISON WITH GELS IN THE SiO2-ZrO2 SYSTEM |
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Takashi WAKASUGI, Anucha WANNAGON, Rikuo OTA, Toshiyuki HORAI, Tetsuso ITAKURA and Jiro FUKUNAGA |
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CHANGE IN RESIDUAL STRESSES OF TiN FILMS DUE ANNEALING TREATMENTS |
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Tatsuya MATSUE, Takao HANABUSA and Yasukazu IKEUCHI |
45 |
DETECTION OF THERMAL AGING OF DUPLEX STAINLESS STEELS WITH SQUID MAGNETOMETER |
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Yoshihiro ISOBE and Toyokazu AOKI |
51 |
SIMULTANEOUS DEEP DRAWING AND STRETCH FORMING OF KNITTED FABRIC COMPOSITE SHEET |
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Teik Cheng LIM, Seeram RAMAKRISHNA and Huai Min SHANG |
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Vol.5 No.1 ABSTRACT
SOLID MECHANICS UNDER MAGNETIC FIELD
Eiji MATSUMOTO
Abstract:This paper reviews the basis of mechanics for deformable electromagnetic materials, their typical behaviors under the magnetic field and applications utilizing coupled phenomena of magnetism and mechanics. Electromagnetic field equations and the conservation laws for moving deformable materials are laid down, on the basis of continuum theory of electromagnetic materials. If such a material is under the magnetic field, it is subjected to several kinds of magnetic forces. Further if the material is electrically conductive and the magnetic field is changing in time, there may also exist the eddy current, the induced magnetic field, the Lorentz force, etc. In the case of ferromagnetic materials, can not be neglected the magnetic nonlinearity, the hysteresis and the magnetomechanical effects such as magnetostriction and stress-dependence of magnetization. In many cases, the magnetic field is static, periodically changing in time, or applied to the demagnetized material. In these cases, the equilibrium theory of deformable magnetic materials can be applied to each magnetization process in which the magnetic field is changing in one-direction including the case of rotating magnetic fields. Mechanical properties under such magnetic fields and the magnetization properties under the stress are discussed. As related topics to the above phenomena, introduced are magnetoelastic problems, nondestructive evaluations of material properties and deformation, and applications of magnetic forces. Key Words:Continuum mechanics, Electromagnetic material, Electromagnetic force, Magnetic field, Magnetization, Magnetostriction, Maxwell equations, Nondestructive evaluation, Electromagnetic actuator, Intelligent material
STRESS-STRAIN RESPONSE OF ROCK-FORMING MINERALS BY MOLECULAR DYNAMICS SIMULATION
Yong-Seok SEO, Yasuaki ICHIKAWA and Katsuyuki KAWAMURA
Abstract:We show a series of molecular dynamics (MD) simulation to determine material properties (i.e., the elastic moduli and the strength) of quartz, muscovite and albite under uniaxial compression and shearing. Note that these are major rock-forming minerals of granite, and are of anisotropic properties. Interatomic potentials are essentially important for the MD calculation) and we used a generalized potential function [1]. MD basic cells imposed are composed of 900 atoms for quartz, 936 atoms for albite and 1,512 atoms for muscovite, respectively. Calculated results acre agreeable compared with experimental data. Key Words:Molecular dynamics, (NPT)- and (NVT)-ensembles, 2-body interatomic potential, Elastic compliance, Elastic stiffness
Takashi MATSUMURA and Masahiro ICHIKAWA
Abstract:In estimating the maximum crack length in a structural component by statistics of extremes, one encounters the problem of how to choose the sample area S (the ratio of the sample area to the whole area) and the number of divisions m. In a previous paper, the present authors showed that the root-mean-square error of the estimated value, SQRT(V(Xmax)) can be approximated by a linear function of log S for the case where individual crack lengths follow an exponential distribution. In the present paper, by conducting a theoretical analysis and Monte Carlo simulation, it is shown that SQRT(V(Xmax))/s can be approximated by a linear function of log T regardless of the distribution forms of individual crack lengths, where a is the standard deviation of the double exponential distribution which the largest crack length in each elemental area follows- and T(= m/S) is the return period. It is also shown that SQRT(V(Xmax))/s by Monte Carlo simulation is 1.1 to 1.9 times larger than that calculated by theoretical analysis. Causes for this difference are discussed. Key Words:Reliability, Maximum crack length, Remaining life, Extreme value analysis, Monte Carlo simulation
Xiangsheng ZENG, Hideki YAMANE, Masaoki TAKAHASHI and Toshiro MASUDA
Abstract:Fourier-transform infrared spectra (FTIR) measurement was made on zinc and sodium ionomers (EMAA-Zn and EMAA-Na) of ethylene-co-methacrylic acid copolymer. It was found that the asymmetry stretching vibration peak of C-O bond of COO- group in ion aggregates of EMAA-Na appeared at lower wavenumber, compared with EMAA-Zn. This means that complete and stable ion aggregates exist in EMAA-Na. Differential scanning calorimetry (DSC) measurement showed that endotherm peak (T1) in lower temperature range resulted from melting of subcrystallites or crystalline ethylene in EMAA and EMAA ionomers. Tensile properties and dynamic viscoelasticity of EMAA greatly changed with the introduction of ionic groups. Key Words:Ionomers, Ethylene-co-methacrylic acid copolymer, Dynamic mechanical properties, Thermal properties, Tensile properties, Ion aggregates
XiangSheng ZENG, Hideki YAMANE, Masaoki TAKAHASHI and Toshiro MASUDA
Abstract:Fourier-transform infrared spectra (FTIR) measurement was made on zinc and sodium ionomers (EMAA-Zn and EMAA-Na) or ethylene-co-methacrylic acid copolymer. Asymmetry stretching vibration peak of ion aggregates in EMAA-Zn changed greatly with slowly cooling process, compared with EMAA-Na. DSC measurement showed that the peak temperature (T) in lower temperature range and its endotherm (AH) increased with the slowly cooling process. The results of dynamic viscoelasticity and tensile measurements indicated that storage modulus, Young's modulus, yield stress, and tensile strength of EMAA ionomers increased greatly with the slowly cooling process. Key Words:Ionomers, Ethylene-co-methacrylic acid copolymer, Dynamic viscoelasticity, Thermalproperties, Thermal history
THERMAL STABILITY OF RF-SPUTTERED AMORPHOUS FILMS IN COMPARISON WITH GELS IN THE SiO2-ZrO2 SYSTEM
Takashi WAKASUGI, Anucha WANNAGON, Rikuo OTA, Toshiyuki HORAI, Tetsuso ITAKURA and Jiro FUKUNAGA
Abstract:Amorphous-forming regions in the RF-sputtered SiO2-ZrO2 films determined by X-ray diffraction were in the range 0-70 mol% ZrO2 under sputtering power 50 W, sputtering time 15 h and in the range 0-68 mol% ZrO2 under sputtering power 100 W, sputtering time 25 h with Ar/O2=3 atmosphere. Crystallization temperatures, TC, measured by DTA on the sputtered films decreased with increasing ZrO2 content. From the liquidus temperature, TL, of the system the thermal stability of the sputtered films was evaluated in terms of TC/TL ratio, which means the amorphous-forming ability, ability of the system to form an amorphous phase. TC/TL ratio decreased with increasing ZrO2 content from 0.81 (0 mol% ZrO2) to 0.36 (69.1 mol% ZrO2) in the sputtered films. Gels of the SiO2-ZrO2 system were prepared from Si(OC2H5)4 and Zr(OC3H7)4 ethanol solution with or without water addition in the range 0-100 mol% ZrO2. TC was measured on dried and calcined gels by DTA. The thermal stability, TC/TL, of gels was found to decrease from 0.77 (0 mo1% ZrO2) to 0.23 (100 mo1% ZrO2). The compositional dependence of TC/TL ratios of gels was almost comparative with those of the sputtered films, implying that amorphous-forming ability is intrinsic to the system. Key Words:SiO2-ZrO2 system, Gels, Sputtered films, Crystallization temperature, Thermal stability, Amorphous-forming ability
CHANGE IN RESIDUAL STRESSES OF TiN FILMS DUE ANNEALING TREATMENTS
Tatsuya MATSUE, Takao HANABUSA and Yasukazu IKEUCHI
Abstract:The structure and residual stresses of TiN films deposited on a steel substrate were investigated by X-ray diffraction. TiN films approximately 4 mm thick were deposited on one side of the substrate by thermal chemical vapor deposition (TiNCVD film). The TiNCVD film exhibited high (100) orientation. The two-exposure method was used to evaluate residual stresses in the TiN films by measuring lattice strains in the directions determined by the crystal orientation of the film. The TiNCVD films had the compressive residual stress of -1.8 GPa, which is as large as the thermal residual stress expected from a thermal strain mismatch between the film and the substrate. The residual stresses did not change by annealing at temperatures below 1073 K, but they increased with increasing annealing temperatures above 1073 K, almost along with the thermal residual stresses. By X-ray photoelectron spectroscopy (XPS), we determined the ratio of nitrogen to titanium (N/Ti) after the annealing treatments. The results of the XPS analysis showed that the initial value of N/Ti was about 1.08 in the as-deposited TiN films and that the ratio of N/Ti did not change after annealing at temperatures below 1073 K, but decreased to 1.00 after annealing at temperatures above 1073 K. Key Words:Titanium nitride, Chemical vapor deposition, X-ray diffraction, X-ray photoelectron spectroscopy, Residual stress, Annealing treatment
DETECTION OF THERMAL AGING OF DUPLEX STAINLESS STEELS WITH SQUID MAGNETOMETER
Yoshihiro ISOBE and Toyokazu AOKI
Abstract:Thermal aging of several duplex stainless steels was detected by an ultrahigh sensitive magnetic sensor using superconducting quantum interference device (SQUID). It was found that the SQUID output signal pattern in the presence of AC magnetic field applied to the specimen was sensitive to very small amount of material property changes due to thermal aging at the operating temperature of light water reactors (LWRs). The change in the SQUID output strongly depended on aging temperatures and ferrite contents of unaged duplex stainless steel specimens. Key Words:Thermal aging, Duplex stainless steel, Nuclear power plant, Primary piping system, SQUID
SIMULTANEOUS DEEP DRAWING AND STRETCH FORMING OF KNITTED FABRIC COMPOSITE SHEET
Teik Cheng LIM, Seeram RAMAKRISHNA and Huai Min SHANG
Abstract:In sheet metal forming, the occurrence of localized necking sets the limit in which the blank can be further formed. Previous studies have shown that sheet formability is governed by the complex interplay between pure stretching and pure deep drawing. Butted fabric composite sheets, which exhibit excellent stretchability and drapeability, can be easily formed into shells of revolution. As in sheet metal forming, the forming conditions (such as blank holding load, blank size and tool geometry) govern the extent to which the fabric composite sheets can be formed. This paper first introduces a new parameter X which describes the amount of stretching relative to drawing during forming. It will be seen that forming processes, specified by the use of various combinations of forming conditions, can be characterized by the parameter X. Finally, the overall formability of knitted fabric composite sheet is discussed with reference to X. Key Words:Textile composites, Knitted fabrics, Thermoplastics, Deep drawing, Stretch forming, Processing