日本機械学会論文集A編
Online ISSN : 1884-8338
ISSN-L : 1884-8338
78 巻, 790 号
選択された号の論文の19件中1~19を表示しています
特集:日本機械学会 発電用設備規格
巻頭言
ノート
  • 永田 徹也, 朝田 誠治
    2012 年 78 巻 790 号 p. 772-777
    発行日: 2012年
    公開日: 2012/06/25
    ジャーナル フリー
    Rules on Material, Design and Construction for Nuclear Power Plants, Div. 1 Light Water Reactors (LWRs) has been developed to stipulate detail requirements for structural design and fabrication of the equipments of nuclear power plants (LWRs). Now this rule is used instead of the abolished MITI (Ministry of International Trade and Industry) Ordinance 501. Here the features and technical topics of this rule are introduced and the future activities are discussed.
  • 浅山 泰, 中山 康成
    2012 年 78 巻 790 号 p. 778-782
    発行日: 2012年
    公開日: 2012/06/25
    ジャーナル フリー
    JSME Rules on Design and Construction for Nuclear Power Plants, Division 2 Fast Reactors have been developed as a set of technical requirements applied to the design and construction of the components of fast breeder reactors operated at elevated temperatures. This report describes the outline of the code. The structure of the code is similar to the ASME Boiler and Pressure Vessel Code Section III Division 1 Subsection NH. However, based on the research and development for the Prototype Fast Reactor “Monju”, a number of original Japanese technologies have also been implemented.
  • 北条 公伸, 釜谷 昌幸
    2012 年 78 巻 790 号 p. 783-788
    発行日: 2012年
    公開日: 2012/06/25
    ジャーナル フリー
    Nickel based alloy is used for light water reactor power plant components such as penetration nozzles and butt weld nozzles of reactor vessels. In recent years, stress corrosion cracking (SCC) occurred at the nickel based alloy weld joints of the power plants in Japan and foreign countries. Integrity of cracked components is evaluated according to the flaw evaluation procedure prescribed in the maintenance rule issued by The Japan Society of Mechanical Engineers (JSME). However, the latest version (2008 edition) of Rules on Fitness-for-Service for Nuclear Power Plants of JSME maintenance rule does not provide the flaw evaluation procedure for nickel based alloy components. The working group of flaw evaluation of JSME code and standard committee have been involved in establishing the flaw evaluation procedure from 2008 and three code cases were published by JSME. This paper introduces the brief contents of the code cases for flaw evaluation for nickel based alloy components.
  • 山本 智, 野村 友典
    2012 年 78 巻 790 号 p. 789-793
    発行日: 2012年
    公開日: 2012/06/25
    ジャーナル フリー
    Rules on Repair, Replacement Activities (RRA) in Nuclear Power Plants (NPP) Fitness-For-Service (FFS) Code of the Japanese Society of Mechanical Engineers (JSME) have been under development since the 2004 Edition. It standardizes general requirements of the RRA rules and various kinds of repair method of construction. However, the RRA rules have been estimated as insufficiency for FFS Code by Japanese regulatory authorities. As the reason, they pointed out that the RRA rules and the regulatory standards are not directly comparable, and the RRA rules are not systematically arranged in relation to inspection and flaw evaluation rules of the JSME FFS Code. To resolve this issue, Task Group on development of RRA rules was organized under the Subcommittee on JSME FFS Code in order to restructure the RRA rules so as be more systematic. The result of the Task Group was reflected in the 2010 addenda of FSS Code 2008 Edition. In addition, the standardization of the new repair method such as Weld Overly (WOL) and New Peening, e.g., Ultrasonic Peening (USP) and Laser Peening (LP), is planned in the RRA rules recently.
  • 西口 磯春, 稲田 文夫, 小島 千秋, 渡辺 豊, 高守 謙郎, 大平 拓, 中村 晶
    2012 年 78 巻 790 号 p. 794-798
    発行日: 2012年
    公開日: 2012/06/25
    ジャーナル フリー
    A large bore carbon steel pipe of a PWR secondary system ruptured in Mihama 2 with some victims in 2004. The Japan Society of Mechanical Engineers (JSME) established the rules for pipe-wall-thinning management by 2006 under the Main Committee on Power Generation Facility Codes (MC-PGFC) to prevent such pipe ruptures. The rules cover the entire system of pipe-wall-thinning management including determining the pipeline to be inspected, the timing and the methods of inspection, evaluation of remaining period for fit for service, and repair and replacement of pipeline. Since the rules were established in a short term, some issues were pointed out to enhance the rules such as a screening method of inspection points, prediction methods of thinning rate, inspection methods, repair methods, etc. Improvement of the rules is one of the major issues in many of organizations. In this note, the roadmap of R&Ds to enhance the rules is described, which MC-PGFC established in 2007, and revised in research committee continuously in JSME.
  • 高橋 由紀夫, 戸村 典章
    2012 年 78 巻 790 号 p. 799-803
    発行日: 2012年
    公開日: 2012/06/25
    ジャーナル フリー
    Japan Society of Mechanical Engineers has developed various guidelines in relation to structural integrity of nuclear and fossil power plants. The guideline for evaluating modes and consequences of potential failure in particular part of piping system in nuclear power plants is one of them. Main part of this procedure is dedicated to the evaluation of likelihood of leak-before-break behavior and evaluation of leak rate. Leak-before-break evaluation requires prediction of fatigue crack growth from a prescribed initial flaw until penetration, calculation of crack length providing detectable leak as well as that causing unstable fracture. Specific guidance is given for each part. This paper discusses the scope and the outline of the present guideline.
  • 西村 新, 中嶋 秀夫
    2012 年 78 巻 790 号 p. 804-807
    発行日: 2012年
    公開日: 2012/06/25
    ジャーナル フリー
    To confirm design and construction process of large superconducting magnets for fusion application, a rules on superconducting magnet structure has been established as part of a code for fusion facilities in JSME standard. The code consists of Quality assurance, Materials, Design, Fabrication and installation, Non-destructive examination, Pressure and leak testing and Glossary. This code is the world first document covering all manufacturing processes of the large scale superconducting magnet for fusion. This report deals with “Structural materials” in the code. Although the code specifies all materials applicable to the magnet construction, the cryogenic structural materials will be focused and the outline of the contents will be expounded here. A special point described in the code is skipping of mechanical tests at cryogenic temperature. When the chemical composition and mechanical property at ambient temperature meet with the code requirements, according to the code and when any special and additional heat treatments are not performed, the cryogenic mechanical tests are not required.
材料力学,機械材料など
一般論文
  • 近藤 俊之, 今岡 貴裕, 平方 寛之, 米津 明生, 﨑原 雅之, 箕島 弘二
    2012 年 78 巻 790 号 p. 808-816
    発行日: 2012年
    公開日: 2012/06/25
    ジャーナル フリー
    We developed an experimental technique for evaluating fatigue crack propagation properties of freestanding nano-films and conducted tensile and fatigue crack propagation experiments for about 500-nm-thick freestanding copper (Cu) films. We employed a sacrificial etching method for fabricating freestanding metallic nano-film specimens. A piezoelectric-actuator with long stroke and a load cell for small load were used for applying cyclic loading to nano-films. We developed original jigs for handling and aligning the nano-film specimens. Focused ion beam (FIB) was employed to introduce a single side-edge-notch in the nano-film specimens for fatigue crack propagation experiments. The results of tensile experiments revealed that the nano-films have resistance to plastic deformation comparable to cold-rolled Cu bulk, but have lower ductility. The results of fatigue crack propagation experiments revealed that a fatigue crack stably propagates in the nano-film by a uniaxial cyclic loading with constant maximum stress before unstable fracture. The fatigue crack propagation rate da/dN of the Cu nano-films is higher than that of Cu bulk counterpart in higher stress intensity factor range, ΔK. Fatigue crack started to propagate from the notch tip below the threshold value of Cu bulk with coarse grains, and the Cu nano-films show similar fatigue crack propagation properties to Cu bulk with ultrafine grains in lower ΔK. Morphology of the fracture surface transited from microstructure-sensitive rough surface to microstructure-insensitive ductile surface or chisel point fracture as fatigue crack propagated. This suggests that the dominant fracture mechanism changes from the accumulation of cyclic deformation to the monotonic tensile-dominant fracture.
  • 加藤 英晃, 古賀 良佑, 粕谷 平和
    2012 年 78 巻 790 号 p. 817-828
    発行日: 2012年
    公開日: 2012/06/25
    ジャーナル フリー
    Motor vehicles on the market are required to undergo the pedestrian head protection test since 2004 and engine-hoods need to meet the required standards for pedestrian head protection performance in addition to primary performance. The engine-hood of motor vehicles is evaluated by the pedestrian head protection performance test according to the Head injury criteria (HIC) which is calculated by 3-dimensional coordinate (x, y, z) of acceleration generated on the head impactor. All car manufacturers are recently required to consider protecting pedestrian heads when developing the engine-hood. It is important to control the acceleration time history at the initial stage and late stage for pedestrian head protection. The engine-hood for pedestrian head protection needs to control local rigidity and whole rigidity by just one structure. To solve this problem we focus on inner panels which have a dominant role in absorbing energy. This study also aimed at evaluating the impact characteristics of inner panels adopting folded panels to improve pedestrian head protection by numerical analysis. As a result, it was found that the inner panel could complement the performance of outer panel. In addition, the folded panel structure help to control the amount of displacement and it was effective in the reduction of HIC.
  • 荒井 正行, 熊谷 知久
    2012 年 78 巻 790 号 p. 829-842
    発行日: 2012年
    公開日: 2012/06/25
    ジャーナル フリー
    In this paper, finite element formulation based on the nonlinear elastic constitutive equation of ceramic thermal barrier coatings is presented. The finite element code that was developed according to the formulation is employed to analyze the problem of the coatings with surface-type and lamination-type cracks which are subjected to a tensile loading. By performing the numerical analysis, it is shown that the stress field around the tip of crack can be expressed as the multiplying form of angular function and stress singularity solution which is characterized by HRR singularity. The damage field, which is associated with micro crack initiation in splat structure, in a lamination-type crack spreads along the crack plane. The other damage field in a surface-type crack is also formed along the plane normal to the crack plane. The inhomogeneity of damage field developed ahead of the crack tip may give a physical explanation for TBC spallation which is known as serious damage observed in actual gas turbine blades.
  • 山本 剛, 白須 圭一, 野坂 陽, 大森 守, 高木 敏行, 橋田 俊之
    2012 年 78 巻 790 号 p. 843-854
    発行日: 2012年
    公開日: 2012/06/25
    ジャーナル フリー
    Alumina composites reinforced with multi-walled carbon nanotube (MWCNT) content up to 3.7 vol.% were prepared by precursor method. The MWCNT used in this study were modified with the acid treatment for 0-4 hours. The rationale behind the acid treatment was to introduce nanoscale defects and adsorb negatively charged functional groups on the surface of the MWCNT. In order to evaluate the effects of the acid treatment of the MWCNT on the mechanical properties and nano/microstructures of the composites, we investigated the dispersibility of MWCNT and morphology of the fracture surface. We found that there was an optimal acid treatment time for improving the mechanical properties of the composites, i.e., the bending strength and fracture toughness of the composites were correlated highly with the dispersibility of the MWCNT in the matrix. The dispersibility of MWCNT and mechanical properties of the composites were simultaneously increased up to 2 hours, and then they were decreased gradually with increasing acid treatment time. TEM observations revealed that peel-off of a few layers in the MWCNT structure was observed for the MWCNT powders acid-treated for 3 and 4 hours. These results implied that the excessive acid treatment of the MWCNT resulted in degradation of the dispersibility of MWCNT and mechanical properties of the composites. This may be due to the decrease in the number of the negatively charged functional groups by the peel-off of a few layers in the MWCNT structure.
  • 山崎 美稀, 岩崎 富生
    2012 年 78 巻 790 号 p. 855-864
    発行日: 2012年
    公開日: 2012/06/25
    ジャーナル フリー
    For the stabilization of insulation performance in the resin-molded insulators, strong adhesion between the resin and metal is required. In this paper, influence of surface roughness for interfacial strength between the resin and metal was investigated. Test pieces were made by covering Cu and SUS cylinders, which have some values of surface roughness, with epoxy resin. The interfacial strength was evaluated with shearing tests of these test pieces. The effective adhesive surfaces of those cylinders were evaluated from surface observation with a laser microscope. The interfacial strength increased with surface roughness. The adhesion-strength index (μ+B), which had been proposed in previous paper, were calculated with the effective adhesive surface and the interfacial strength. The adhesion-strength index gave a constant value with various surface roughnesses for each metal.
  • 堀川 教世, 野村 幸弘, 北河 享, 春山 義夫, 境田 彰芳, 今道 高志, 上野 明
    2012 年 78 巻 790 号 p. 865-878
    発行日: 2012年
    公開日: 2012/06/25
    ジャーナル フリー
    The effects of low-intensity UV light irradiation on tensile strength of high-modulus (HM) type poly-p-phenylene benzobisoxazole (PBO) fiber improved tensile modulus by heat-treatment were investigated in a monofilament tensile test. Irradiation time was set to 0 h, 1 h, 10 h, 100 h and 1,000 h, while radiance were arranged to become 2, 4 and 8 W/m2. Standard modulus (As spun: AS) type PBO fiber that authors reported its properties before was employed as standard specimen. It was found that the tensile strength distribution of UV irradiated HM type fiber could be approximated to a normal distribution. The relation between tensile strength and radiation time depend on the degree of radiance. However, the relation between tensile strength and radiation dosage was independent of the degree of radiance, and the radiation dosage was most suitable parameter to describe the tensile strength at the different radiance. The tensile strength of HM type fiber was higher than that of AS type fiber over all radiation dosage. It was found by AFM observation that amount of the surface roughness on the UV irradiated HM type fiber with increasing the radiation dosage was smaller than that of the UV irradiated AS fiber. The reason for that poor crystallite orientation region in HM fiber was less than that in AS fiber and an increase in roughness causes autoxidation occur predominantly in the poor crystallite orientation region. Thus the decrease in tensile strength of fibers under UV light irradiation was attributable to not only cutting an internal molecule by the exposure to UV radiation but also the roughness on the surface of the fiber. Effect of roughness on the tensile strength of the UV irradiated HM type fiber was smaller than that of AS type fiber. However, the effect of roughness on the tensile strength of both fibers was not very large.
  • 和田 明浩, 元木 信弥, 山崎 友裕
    2012 年 78 巻 790 号 p. 879-889
    発行日: 2012年
    公開日: 2012/06/25
    ジャーナル フリー
    A new technique using Lamb waves has been proposed to detect impact damages in FRP laminates nondestructively. Conventional ultrasonic testing such as C-scan requires two-dimensional scanning for whole area inspection because the inspected area by one operation is relatively small. In this study, for quick detection of a localized defect, spectrum analysis of Lamb waves is demonstrated. Instead of wave velocity or attenuation, acousto-ultrasonic parameters (AU parameters), which are based on the amplitude spectrum of the broadband signal, are introduced to improve the precision of the inspection. Among the several AU parameters, A2 and A4/A3 parameters, which represent the centroid and the torsion of the spectral density curve respectively, are found to be more useful to identify a localized defect in laminated composite plates. It is also found that the inspection accuracy depends on the wave propagation direction reflecting to the scattering of higher frequency waves, and can be improved by use of burst waves.
  • 樋口 理宏, 足立 忠晴, 吉岡 大志, 横地 雄斗
    2012 年 78 巻 790 号 p. 890-901
    発行日: 2012年
    公開日: 2012/06/25
    ジャーナル フリー
    We investigated mechanical properties in functionally graded syntactic foams which have graded distribution of Acrylonitrile hollow particles (micro-balloons) in epoxy resin matrix. In order to control the distributions of the mechanical properties, the density distributions in the foams were graded by floating phenomenon of the micro-balloons in the matrix resin during the curing process. The dynamic viscoelastic measurements and static compression tests were conducted to evaluate local mechanical properties of the functionally graded syntactic foams. Dynamic viscoelastic measurements revealed that the thermo-viscoelastic properties of the fabricated foams were determined by the properties of the epoxy matrix resin. The static compression test provided relations between the mechanical properties (the compressive Young's modulus and yield stress) and the density in the functionally graded syntactic foams. Consequently, the distributions of the mechanical properties in the functionally graded syntactic foams were identified from the density distribution.
  • 藤井 朋之, 東郷 敬一郎, 島村 佳伸, 和田 拓也, 伊藤 洋一, 片山 信行
    2012 年 78 巻 790 号 p. 902-911
    発行日: 2012年
    公開日: 2012/06/25
    ジャーナル フリー
    This paper deals with the debonding behavior of paper-based friction materials under out-of-plane tensile loading. Double cantilever beam tests were carried out for four kinds of friction materials in order to evaluate the debonding fracture toughness and clarify the influence of constituents on fracture toughness. The constituents of the friction materials are aramid, cellulose, carbon fiber, filler and phenolic resin. From the double cantilever beam tests, the following results were obtained: (1) The debonding fracture toughness of the friction materials can be estimated by using double cantilever beam test for interlaminar fracture toughness of laminated composites. (2) The debonding fracture resistance of the friction materials increases with crack extension, and becomes constant after the crack extension reaches 50mm. (3) The debonding fracture toughness is enhanced by aramid fibers and decreased by carbon fibers. The influence of the constituents on debonding fracture toughness agrees with that on in-plane fracture toughness. (4) SEM micrographs of fracture surface imply that fibrillation of aramid fibers increases the debonding fracture toughness.
  • 松田 伸也, 黄木 景二
    2012 年 78 巻 790 号 p. 912-922
    発行日: 2012年
    公開日: 2012/06/25
    ジャーナル フリー
    This paper presents a probabilistic model for predicting the constant fatigue life (CFL) diagrams for ceramics. First, a unified probabilistic delayed-fracture (PDF) model was proposed on the basis of the slow crack growth (SCG) concept in conjunction with the two-parameter Weibull distribution. Second, probabilistic CFL diagrams for effective volume Veff, effective loading time teffNf, fracture probability F and stress ratio R were obtained using the PDF model. The probabilistic CFL diagram was then related with the modified Goodman's diagram. Third, the unified strength parameters associated with the PDF model were determined using the experiment data of Si3N4 subjected to rotating bending. The stress amplitude - the number of cycles to failure curves were then predicted for R=-1 and 0 and various values of F. Moreover, the probabilistic CFL diagrams for various values of Veff and teffNf at F were depicted using the unified strength parameters. The validity of the present model was confirmed through the comparison of the predicted CFL diagrams with the experiment data.
ノート
  • 長島 伸夫, 古谷 佳之, 木村 勇次, 井上 忠信
    2012 年 78 巻 790 号 p. 923-927
    発行日: 2012年
    公開日: 2012/06/25
    ジャーナル フリー
    Giga-cycle fatigue properties were investigated for an ultrafine-grained steel processed by warm tempforming. The fatigue properties of the tempformed (TF) steel were compared with conventional tempered martensite (QT) steel. Fatigue tests were carried out at frequencies of 20Hz and 20kHz, using servo-hydraulic and ultrasonic fatigue testing machines, respectively. Both theTF and the QT steels showed surface fracture in short life regions and fish-eye fracture in long life regions. The fish-eye fracture origins were oxide inclusions comprised of Si, Mg, Ca other than Al. Difference of fatigue strength was not notable between the TF and the QT steels, i.e. the fatigue strength of the TF steel was the same as that of the QT steel.
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