Vol. 7 No. 1 CONTENTS
General Papers (Vol.7 No.1)
Variation in Preferred Orientations of TiN Thin Films Prepared by Ion Beam Assisted Deposition |
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Akihito MATSUMURO, Toshiyuki HAYASHI, Mutsuo MURAMATSU, Yutaka TAKAHASHI, Masao KOHZAKI and Katsumi YAMAGUCHI |
1 |
The Effect of Microcracks on the Mechanical Anisotropy of Granite |
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Sang-Eun LEE, Sang-Ho CHO, Yong-Seok SEO, Hyung-Sik YANG and Hong-Min PARK |
7 |
Analysis on the Flexural Behavior of Externally Prestressed Beam with Large Eccentricity by the Method of Moment-Curvature Relationship |
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Fang DEPING, Toyoaki MIYAGAWA and Takashi YAMAMOTO |
14 |
Simulation of the Forging Process Incorporating Strain-Induced Phase Transformation Using the Finite Volume Method (Part I ; Basic Theory and Numerical Methodology) |
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Peiran DING, Tatsuo INOUE, Shoji IMATANI, Dong-Ying JU and Edwin de VRIES |
19 |
Simulation of Forging Process Incorporating Strain-Induced Phase Transformation Using the Finite Volume Method (Part II ; Effects of Strain Rate on Structural Change and Mechanical Behavior) |
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Peiran DING, Dong-Ying JU, Tatsuo INOUE, Shoji IMATANI and Edwin de VRIES |
27 |
Effects of Interface Control and Heat-Treatment Temperature on Interlaminar Shear Strength and Mode II Interlaminar Fracture Toughness of Woven C/C Composites |
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Masaki HOJO, Taketoshi YAMAO, Mototsugu TANAKA, Shojiro OCHIAI, Norio IWASHITA and Yoshihiro SAWADA |
34 |
A Study on the Influence of Mechanical Properties on the Distribution of Axial Residual Stress after Cold Drawing of Metallic Bars |
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Takashi KUBOKI, Ishine KAWAKAMI, Yutaka NEISHI, Kouichi KURODA and Masayoshi AKIYAMA |
41 |
Improvement of Mechanical Properties of Ferrum Lime Stabilized Soil with the Addition of Aluminum Sludge |
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Masashi KAMON, Huanda GU and Masahiro I |
47 |
Residual Stress and In-situ Thermal Stress Measurements of Copper Films on Glass Substrate |
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Takao HANABUSA and Masayuki NISHIDA |
54 |
Quality Evaluation of Molded Epoxy Resin and Particulate Filled Composites by Ultrasonic Technique |
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Kazuyoshi ARAI, Wen Fa LI, Shigeru ONO, Akira KANETAKA and Hidemitsu HOJO |
61 |
AE Technique for Identification of Micro Failure Modes in CFRP Composites |
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Qing-Qing NI, Ken KURASHIKI and Masaharu IWAMOTO |
67 |
Vol.7 No.1 ABSTRACT
Variation in Preferred Orientations of TiN Thin Films Prepared by Ion Beam Assisted Deposition
Akihito MATSUMURO, Toshiyuki HAYASHI, Mutsuo MURAMATSU, Yutaka TAKAHASHI, Masao KOHZAKI and Katsumi YAMAGUCHI
Abstract:The effects of various experimental conditions on the preferred orientations of titanium nitride (TiN) thin films were investigated. These films were formed on Si (100) wafers and
sapphire (0001) substrates by ion beam assisted deposition (IBAD) with various N/Ti transport ratios, N ion incidence angles, film thicknesses and substrate temperatures. The acceleration voltage of the incident ions was 1 kV. The preferred orientation of the TiN films changed from (111) to (100) as the N/Ti transport ratios and ion incidence angles increased. This phenomenon is caused by the selective damage to crystal growth due to the energy of the bombarding particles. It was also found that an increase in film thickness changed the
preferred orientation of the TiN (100) film to a (100) plus (110) orientation. Furthermore, this orientation reverted to (100) with the heating of the substrate during film preparation. It is concluded that these phenomena were caused by the process of minimizing the overall energy. Thus, the heating of the substrate was useful for synthesizing thick TiN (100) films
in this preparation method. Transmission electron microscopy (TEM) observation of TiN (100)
films suggested that these films had good crystallinity.
Key Words:Titanium nitride, Preferred orientation, Ion beam assisted deposition, Transport ratio,
Incidence angle, Thickness, Temperature
The Effect of Microcracks on the Mechanical Anisotropy of Granite
Sang-Eun LEE, Sang-Ho CHO, Yong-Seok SEO, Hyung-Sik YANG and Hong-Min PARK
Abstract:Granite is a brittle material and contains numerous small defects which are preferentially oriented along three mutually perpendicular quarry planes. These defects affect the physical properties of the granite, such as p-wave velocity, tensile strength, and compressive strength. In the present paper, we are reporting mechanical anisotropy of Nangsan and Hamyeol granite produced in Korea. P-wave velocity and Brazilian tensile strength were measured in diametric direction at a 10interval. A uniaxial compressive test was carried out with measuring two diametric strains of quarry planes which are parallel to load. The result shows a strong correlation between crack density and other mechanical properties.
Key Words:Granite, Mechanical anisotropy, P-wave velocity, Tensile strength, Uniaxial strength
Analysis on the Flexural Behavior of Externally Prestressed Beam with Large Eccentricity by the Method of Moment-Curvature Relationship
Fang DEPING, Toyoaki MIYAGAWA and Takashi YAMAMOTO
Abstract:In this paper, the M-N- relationship of a beam section and the calculation of deformation for the externally prestressed tendon with large eccentricities are studied. A general method for analyzing the stress@increment of external tendon and beam flexural behavior is presented. In this method, the action of external tendon is expressed as the equivalent loads applying at the deviators and anchorage ends. The beam not including external tendon is subjected to bending moment and axial force caused by both applied loads and equivalent loads. By comparing the different positions of deviators and anchorage ends before and after loading, the force of external tendon is obtained, the deformation compatibility of the external tendon is met, and the loss of tendon's eccentricity can be considered auto-matically. The calculation results conform well to the experimental results in reference.
Key Words:External prestressing, Flexural strength, Large eccentricity, Moment-curvature, Prestressed concrete, Continuous beams
Simulation of the Forging Process Incorporating Strain-Induced Phase Transformation Using the Finite Volume Method (Part I ; Basic Theory and Numerical Methodology)
Peiran DING, Tatsuo INOUE, Shoji IMATANI, Dong-Ying JU and Edwin de VRIES
Abstract:A method to simulate the forging process and corresponding strain-induced austenitic-martensite phase transformation is formulated in the Eulerian description and its feasibility is examined. The method uses finite volume meshes for tracking material deformation and an automatically refined facet surface to accurately trace the free surface of the deforming material. By means of this finite volume method, an approach has been developed in the framework of metallo-thermo-mechanics to simulate metallic structure, temperature and stress/strain in the forging process associated with phase transformation. The incremental expression on the formulation of the kinetics equation is derived from Tsuta and Cortes' model. A mixture rule is adopted to evaluate the aggregate flow stress of the austenite-martensite affected by the respective flow stresses and phase transformation. This approach has been implemented in the commercial computer program MSC.SuperForge. This is the first report in which the fundamental framework is stated and the applicability of the developed method is confirmed using experimental results of the forging of a cylindrical billet. Some practical forging applications are demonstrated in the second report.
Key Words:Finite volume method, Explicit time integration, Strain-induced phase transformation, Incremental formulation of kinetics equation, Metallo-thermo-mechanics, Forging, SUS304 stainless steel
Simulation of Forging Process Incorporating Strain-Induced Phase Transformation Using the Finite Volume Method (Part II ; Effects of Strain Rate on Structural Change and Mechanical Behavior)
Peiran DING, Dong-Ying JU, Tatsuo INOUE, Shoji IMATANI and Edwin de VRIES
Abstract:In Part I, based on the framework of metallo-thermo-mechanics, a finite volume method formulated in the Eulerian description has been set up to simulate the forging process and corresponding strain-induced austenitic-martensite phase transformation. The approach has been developed and implemented in the commercial computer program MSC.SuperForge. In this paper, numerical simulations for SUS304 stainless steel on backward and forward extrusions are carried out in order to verify the method proposed in Part I. Furthermore, the effects of strain rate on the austenitic-martensite phase transformation and the aggregate flow stress are studied.
Key Words:Finite volume method, Strain-induced phase transformation, Incremental formulation of kinetics equation, Metallo-thermo-mechanics, Forging, SUS304 stainless steel, Strain rate
Effects of Interface Control and Heat-Treatment Temperature on Interlaminar Shear Strength and Mode II Interlaminar Fracture Toughness of Woven C/C Composites
Masaki HOJO, Taketoshi YAMAO, Mototsugu TANAKA, Shojiro OCHIAI, Norio IWASHITA and Yoshihiro SAWADA
Abstract:The effects of interface control and matrix microstructure on the interlaminar shear strength and mode II interlaminar fracture toughness of 5H satin woven C/C composites were investigated by coating bismaleimide-triazine co-polymer (BT-resin) on the surface of carbon fiber and changing the heat-treatment temperature. Three point short beam flexure tests were carried out for the shear strength. End notched flexure specimens were used for the mode II interlaminar fracture toughness tests. Both the interlaminar strength and toughness decreased by coating BT-resin and increasing HTT from 1600 to 2500. However the influence of the BT-resin coating was much larger for the mode II interlaminar fracture toughness than that for the interlaminar shear strength. This difference of the effect of interface control was discussed on the basis of microscopic observation.
Key Words:C/C composites, Interlaminar strength, Interlaminar fracture toughness, Mode II, Interface control, Heat-treatment temperature
A Study on the Influence of Mechanical Properties on the Distribution of Axial Residual Stress after Cold Drawing of Metallic Bars
Takashi KUBOKI, Ishine KAWAKAMI, Yutaka NEISHI, Kouichi KURODA and Masayoshi AKIYAMA
Abstract:Investigation was carried out on the influence of mechanical properties on the intensity of axial residual stress after cold drawing of metallic bars. Yield stress, Young's modulus, and work-hardening ratio were chosen as indications of mechanical properties, and quantitative influence was examined numerically on an ordinary cold drawing. After examining the quantitative influence of mechanical properties on the axial residual stress after drawing,
further numerical experiments were carried out on the skin-pass effect in reducing the intensity of axial residual stress distribution, which the authors presented a result in the previous study by using S45C steel bars. In order to clarify the validity of the numerical analysis, various materials of different mechanical properties were selected, and cold drawing experiments were carried out in a laboratory to check the validity of the numerical results.
The materials selected were (1) high-carbon steel, (2) medium carbon steel, (3) copper, and (4) aluminum. The residual stress was measured by Sachs method, and good agreement was obtained between the calculated and measured results in any case. It was found that the axial residual stress distribution is most sensitive to the work-hardening ratio, and an optimum skin-pass drawing condition was presented by quantitatively examining the effect of skin-pass in reducing the axial residual distribution.
Key Words:Drawing, Residual stress, Mechanical properties, Skin pass
Improvement of Mechanical Properties of Ferrum Lime Stabilized Soil with the Addition of Aluminum Sludge
Masashi KAMON, Huanda GU and Masahiro I
Abstract:This paper describes the effective utilization of industrial wastes such as ferric oxide powder and aluminum sludge for soil stabilization. Mixing these industrial wastes with hydrated lime to form some new type of stabilizers will be useful for both strength improvements of soils and environmental protection. The primary objectiveof this study is to investigate the effect of wastes on the strength development of stabilized soils. To perceive the strength development mechanisms of stabilized soils, X-ray diffraction (XRD) and scanning electron microscopy (SEM) methods were employed in order to evaluate the formation of chemical reaction products and microstructural changes occurred in the stabilized soils. The industrial wastes contained in stabilized soil improve the mechanical properties of soils by chemical reactions between the reacting elements of industrial wastes and clay minerals in the soil. In particular, adding aluminum sludge into ferrum lime lead to a marked improvement in the early strength or flexural strength of stabilized soils.
Key Words:Stabilized soil, Ferric oxide, Aluminum sludge, Unconfined compressive strength, Flexural strength, SEM, X-ray diffraction
Residual Stress and In-situ Thermal Stress Measurements of Copper Films on Glass Substrate
Takao HANABUSA and Masayuki NISHIDA
Abstract:The present study investigates the behavior of residual stress and thermal stress in thin copper films with X-rays. The copper films were deposited on a glass substrate by radio frequency (RF) sputtering. In-situ therm al stress measurement was also made on copper films during heat cycles. The residual stress of as-deposited state was tensile regardless of the conditio ns of film preparation. Early in the cooling stage, thermal stress behaves in an elastic manner so as to reduce the tensile stress until it stabilizes close to zero. In the cooling stage, little increase in the thermal stress was observed above 100 and the hysteresis of thermal cycle was very small.
Key Words:Cu film, Residual stress, In-situ thermal stress, X-ray stress measurement
Quality Evaluation of Molded Epoxy Resin and Particulate Filled Composites by Ultrasonic Technique
Kazuyoshi ARAI, Wen Fa LI, Shigeru ONO, Akira KANETAKA and Hidemitsu HOJO
Abstract:Epoxy resin and its particulate filled composites are being used widely in many fields of industry. High quality as well as reliability are especially necessary for electric and electronic products such as heavy generators and IC packages. For quality assurance, therefore, it is important to detect or evaluate the quality of these materials without causing destroying them. The purpose of this study is to establish a non-destructive evaluation method for the quality of cast epoxy resin and its particulate filled composites. This paper describes the results of an investigation made to clarify the relation among structure, physical and mechanical properties and ultrasonic characteristics of these materials by using an ultrasonic pulse reflection technique.
Key Words:Ultrasonic technique, Quality evaluation, Epoxy resin, Particulate filled composite
AE Technique for Identification of Micro Failure Modes in CFRP Composites
Qing-Qing NI, Ken KURASHIKI and Masaharu IWAMOTO
Abstract:The fundamental characteristics of AE signals, such as the attenuation, frequency dependency of AE signals in CFRP composites, were investigated. The fracture process of the s. f. c. (single fiber composite) was examined. As a result, the frequencies of AE signals were almost unchanged, while AE amplitudes attenuated greatly with the increment of propagation distance. This proves that the frequency analysis is an effective way in processing AE signals of CFRP composites. Using the frequency analysis, the relationships between the micro failure modes and the frequencies at the peaks of the power spectrum distribution were established. In the fracture process of the s.f.c., the sources of AE signals were the failure modes at the fiber breakages. Using the time-frequency method of the short-time Fourier transform to process AE signals in CFRP composites, the micro failure modes at a fiber breakage and the microfracture mechanism, such as the sequence of failure modes
and their interaction, were made clearer. It was shown that two processing methods of AE signals, the frequency analysis and the short-time Fourier transform, were powerful to identify the micro failure modes and elucidate the microfracture mechanisms in CFRP composites.
Key Words:Time-frequency analysis, Short-time Fourier transform, Failure mode, Acoustic emission, Attenuation