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Shizuo HARADA, Yoshihisa MINAKUCHI, Masanobu NAKAMURA
Article type: Article
Session ID: J0401-4-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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We simulated the healing behavior of bone after plate fixation of a diaphyseal fracture using the growth-strain method. The growth criterion parameters on the strain energy density of cortical bone were investigated by applying the finite element method to a three-dimensional model of a normal cortical bone. Next, the fracture healing model fixed using a plate with 4 or 6 screws was analyzed in the case where the clamping force of one screw was 250N. The growth analysis of the diaphyseal fracture was performed using the previously obtained growth criterion parameters. The optimal operation method was in the case where 4 screws were clamped at the nearest bone fracture.
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Shota NAKASUJI, Yusuke MORITA, Kazuto TANAKA, Tsutao KATAYAMA, Eiji NA ...
Article type: Article
Session ID: J0401-4-4
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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It is necessary for the regenerated cartilage to have same mechanical property as natural cartilage in a short period. The purpose of this study is to examine the effect of pulse wave electric field stimulation on activity of chondrocytes. Effect of pulse width, electric field value and frequency were evaluated to determine suitable condition for the stimulation. Isolated chondrocytes from porcine articular cartilage suspended with culture medium, and they were seeded in a custom made culture chamber that has parallel platinum electrodes. Chondrocytes were cultured for two days with electric field stimulation in an incubator. After the cultivation, amount of chondroitin sulfate was measured with DMMB method.
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Nobukazu OKUMURA, Yusuke MORITA, Kazuto TANAKA, Tsutao KATAYAMA, Eiji ...
Article type: Article
Session ID: J0401-4-5
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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The purpose of this study is to investigate the correlation between electrical impedance and mechanical properties of articular cartilage. Collagenase model were prepared to digest collagen fibrils for articular cartilage. Measurement of electric impedance and compressive test were carried out to evaluate electric and mechanical properties of the specimen before and after enzyme treatment. Electric impedance and compressive elastic modulus decreased with increasing treatment time for collagenase treatment. As a result, electric impedance was related to the elastic modulus and viscosity of the articular cartilage. It is suggested that electric impedance method is able to predict mechanical properties of articular cartilage.
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Daisuke HAMADA, Yasushi OKUBO, Koji YAMAMOTO, Shin-ichiro MORI, Kunihi ...
Article type: Article
Session ID: J0401-5-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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The effects of vitamin E added to the ultrahigh molecular weight polyethylene (UHMWPE) on the frictional properties were examined in order to clarify the wear mechanism of vitamin E-containing UHMWPE in knee prostheses. The sample UHMWPE was slid against the surface of a Co-28Cr-6Mo alloy in bovine serum and in ultrapure water lubricants by using a pin-on-disk friction test apparatus. Fresh serum and post-friction (PF) serum and diluted-PF (DPF) serum were used in order to investigate the effects of friction-dependent conformational changes in serum proteins on the frictional properties. Vitamin E-containing UHMWPE showed a significantly higher friction force than that of virgin UHMWPE in fresh serum lubricant at 30 MPa loading, while there were little differences in ultrapure water, PF and DPF serum. These results suggest that the addition of vitamin E to UHMWPE can affect the boundary lubrication state in the presence of native conformation proteins.
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Masayoshi MIZUTANI, Takafumi MIZUNO, Noriyuki HISAMORI, Hitoshi OHMORI
Article type: Article
Session ID: J0401-5-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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Cobalt-Chromium (Co-Cr) alloys possess outstanding corrosion resistance and wear resistance because of passive film of a few nanometers' thickness on their surfaces. In this study, we have clarified the damage accumulation mechanism of Co-Cr alloys under the simultaneous reaction of corrosion and wear in sodium chloride solution. A corrosion wear characteristic of these alloys was evaluated by static polarization test under simultaneous wear damage. Wear was applied using a reciprocating rotational pin-on-flat abrasion machine. The pin material in all tests was polyethylene. Applied loads were 9.8 N. The disk rotation sliding rates were 10, 1.0, and 0.1 mm/s. The results show the current density increases significantly early only when the sliding rate is 10 mm/s. This is thought to occur because the wear on the passive film affects the corrosion reaction. The results also show that the current density drops (recovers) over time and approaches the Control. Therefore, if you assume the prolonged use of implants, the sliding rate in early use greatly affects the corrosion reaction.
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Seido YARIMITSU, Kazuhiro NAKASHIMA, Yoshinori SAWAE, Teruo MURAKAMI
Article type: Article
Session ID: J0401-5-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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The aim of this study is to investigate the influences of subchondral thickness on frictional behavior of articular cartilage. It was found that friction coefficient increased with decrease of the ratio of the thickness of subchondral and eancellous layer to that of cartilage layer. In addition, frictional behavior of natural cartilage is affected significantly when the ratio of the thickness of subchondral and cancellous layer to that of cartilage layer is less than 1.0. It was found that there were little differences in apparent contact area and surtace tnoiphology between cartilage specimen with and without subchondral and cancellous layer. It is hypothesized that the thickness of subchondral and cancellous layer influences on the tranfer of water in cartilage layer and between cartilage layer and subchondral layer, and thus internal stress and hydration behavior of cartilage layer changes. These changes may induce the changes of frictional behavior of natural cartilage.
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Osamu YOKOTA, Ryota UMEDA, Mitsuo NAGAO
Article type: Article
Session ID: J0401-5-4
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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The method for examining the surface texture of the flexible thing, namely softness and the viscoelastic property, has not been clearly established. The contactless testing method which could measure the surface texture was proposed, and the development of the functional equipment was tried. It was proposed with the method for measuring the dents using the compressed air. It is possible to display the softness and the viscoelastic property by the method for measuring diameter and depth of the dents.
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Natsuko HOSODA, Nobuo SAKAI, Yoshinori SAWAE, Teruo MURAKAMI
Article type: Article
Session ID: J0401-5-5
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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Articular cartilage has high water content from 70 to 80% and biphasic property. Articular cartilage is composed of chondrocytes and an extracellular matrix. Extracellular matrix is mainly composed of proteoglycan and collagen, and produced by chondrocytes to provide scaffold to chondrocytes and support load to cartilage. The structural component of the tissue is inhomogeneous and anisotropy. Consequently, cartilage tissue shows complicated viscoelastic behavior to mechanical stimuli because of depth-dependent and time-dependent interstitial fluid flux and stress-strain behaviors. Therefore it is necessary to consider not only the average tissue property but also the local one to explain mechanical and functional behavior. In this study, we created articular cartilage tissue model in unconfined compression test under constant total deformation or constant load and simulated stress relaxation and creep behaviors using finite element method based on biphasic theory.
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Nobuya TAMURA, Koji YAMAMOTO, Keisuke YAMADA, Tsuyosi TERAMURA, Yasuhi ...
Article type: Article
Session ID: J0401-5-6
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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Natural articular joints keep very low friction coefficient despite of severe mechanical conditions. Sasada reported that the hydrogel on cartilage surface plays an important role to keep low friction coefficient. In our previous study, friction coefficient was measured by reciprocating friction-testing apparatus using stainless steel counterface. But it is considered that friction test using stainless steel counterface is inappropriate to evaluate the effect of hydrogel lubrication. 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer is well known as a hydrophilic biocompatible material. In this study, frictional performances of porcine cartilage was evaluated using MPC-polymer grafted silicon counterface to evaluate the surface-gel lubrication.
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Takashi YOKOYAMA, Satoshi IZUMI, Shinsuke SAKAI
Article type: Article
Session ID: J0402-1-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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Analytical model for the mechanical behavior of bolted joint subjected to transverse load has been theoretically formulated. It has been shown that transverse displacement of the bolted joint can be separated into five factors: (a) bolt bending due to transverse force acting on the thread surface, (b) bolt bending due to thread surface reaction moment, (c) inclination of bolt head, (d) thread surface slip, and (e) bearing surface slip. In order to calculate the factors (d) and (e), contact force and slip displacement induced on the contact surfaces are modeled while factors (a) to (c) are formulated according to previous theories. In addition, it has been shown that variation in reaction moment induced on the contact surfaces, which affects (b) to (e), depends on contact state. Then, the relation between the reaction moment and transverse load is formulated. We have applied our analytical model to an MI6 bolted joint and confirmed that the model shows good agreement on the load-displacement relation with FEM result.
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Toshio HATTORI, Minoru YAMASHITA, Takahiro KONDOH, Yoshimizu IIDA
Article type: Article
Session ID: J0402-1-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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Lately there happened many loosening or failure accidents in bolted joints, such as trailer's wheel/hub joint structures and airplane mechanical systems. Put abstract text here. To avoid these accidents and increase the safety for long life operation of these traffic systems we present the idea of fastening force monitoring system, and discuss the availability of these systems in traffic or industrial fields. Lately the semiconductor strain sensor is attracted considerable attention for it's sufficient sensitivity, linearity and stability, so we selected this semiconductor strain sensor as the monitoring sensor. Then we examine the fundamental characteristics of these sensors, and confirm the twenty times higher sensitivity compared with traditional wire strain gages, linearity of less than 3.3% deviation and high stability of less than 1.4%/℃ under temperature change. And we can confirmed the availability of semiconductor strain sensor and wireless data transmission systems for fastening force or loosening behavior monitoring systems of bolted joints.
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Tomohiko OKABE, Atsushi IWASAKI, Kazunori NAKAJIMA
Article type: Article
Session ID: J0402-1-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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This research is about stress analysis of loosening process of bolted joint of CFRP Plate via contact analysis using FEM. Carbon fiber reinforced plastic (CFRP) has high specific tensile strength and stiffness, and are good for the structures of airplanes and space instruments. In recent years, CFRP becomes to use as the major structure of the large airplane like A380. Since the matrix of CFRP is epoxy resin in general, compressive strength of thickness direction is low and the fastening force of bolted joint of CFRP plate is low than that of metal plate joint When the joint is vibrated by external force, side of the bolt hole is compressed by side of the bolt Then in this research, influence the fastening force of the bolted joint and compression force of side of the bolt hole to the loosening process and the internal stress distribution of CFRP plate is investigated by the analysis of loosening process via FEM contact analysis.
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Noboru KUSAMA
Article type: Article
Session ID: J0402-1-4
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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This paper describes failure analysis of roller coaster's cone bolt, in Osaka Exposition amusement park. The bolt of M36 is tough enough for 15 years operation. The police's assumption of fatigue failure has to be reviewed In the people's agreement, there will be uncertainty aversion principle.
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Junji SAKAMOTO, Yoshiyuki KONDO, Masanobu KUBOTA
Article type: Article
Session ID: J0402-1-5
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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The authors showed that the improvement of fretting fatigue strength by stress-relief groove can be evaluated by the stress concentration factor in the vicinity of the contact edge. This evaluation method used a mater curve based on large amount of experiment. The objective of this study is expansion of the evaluation method to reduce the amount of experiment by utilizing FEM analysis. The criterion of fracture that the maximum axial stress was equivalent to the fatigue limit of smooth specimen was confirmed by an S-N test and analysis conditions were fixed by another S-N test. The master curve was then produced by analysis. The result of evaluation was in good agreement with that of experiment. Another objective was to obtain further improvement of fretting fatigue strength by stress-relief groove. 1.75 times increase was achieved by compound arc shape groove.
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Yu KIMURA, Ming YANG
Article type: Article
Session ID: J0402-1-6
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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For the micro molding, influence by the surface property of the die becomes remarkable by scale effect. However, there are a lot of questions about the characteristic of the micro dies surface. In this study, we discussed for establishment of the tribological characteristic evaluation technology in the micro molding processing, developed the tribological characteristic evaluation device of the micro dies and evaluated a dynamic friction characteristic in the micro scale. In addition, we conducted an investigation into the influence by the die surface treatment.
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Masahiro FURUYA, Moriyasu TOKIWAI, Nobuyuki TANAKA, Masaaki Horie
Article type: Article
Session ID: J0402-2-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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In order to store nuclear spent fuels for a long term, we propose the concept of stainless steel canister with titanium cladding. A parametric study on MIG brazing for titanium and stainless steel revealed that Cu-1Mn-3Si alloy (MG960) is promising MIG brazing material. The optimized brazing conditions showed adequate structural strength such as JIS G 0601 shear strength, tensile shear stress and peel strength.
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Hiroyuki NAKANO, Takao MORI, Toshihiko SAYAMA, Takeshi TAKAYANAGI, Yos ...
Article type: Article
Session ID: J0402-2-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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It is important to evaluate the thermal fatigue crack initiation lifetime of Sn-3.0Ag-0.5Cu solder joints in order to improve the reliability of electronic devices. In this paper, in order to clear the phase growth process in the solder joint which has a strain concentration in the end of the joint, the detail finite element analysis of the mini-lap joint type specimen was performed and the strain around the corner of the joint was examined. Consequently, it is clear that the crack initiation life time can be evaluated by using the increment of phase growth parameter at the strain concentration occurring zone as same as PCB specimen.
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Yoko YAMAGATA, Masato MIWA, Hisashi NAKAMOTO
Article type: Article
Session ID: J0402-2-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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In this paper, the fatigue reliability of Sn-3.0Ag-0.5Cu lead-free solder joints was estimated. First, we constructed a plastic-creep constitutive model based on results of tensile tests and creep tests. Then, we conducted FEM analysis of the lead-free solder joint under thermal cycle load. The thermal fatigue life was estimated by comparing inelastic strain energy and low-cycle fatigue test results. As a result, it was confirmed that analysis result was in good agreement with the experimental result.
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Naoki SAHASHI, Masaharu FUJIWARA, Koji KOIBUCHI
Article type: Article
Session ID: J0402-2-4
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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In this paper, the fatigue strength evaluation method by calculating theoretical cyclic plasticity size ω directly from a 3D FEM model was proposed. And the validity was checked by comparison with the 2D FEM model result in Society of Automotive Engineers of Japan. Moreover, in case of a continuous welding-bead model, it pointed out by 3D FEM method that the fatigue prediction diagram came to the high life side rather than the discontinuous welding-bead reported conventionally. And its tendency was confirmed by a fatigue experiment. Thereby, it is able to evaluate the fatigue strength for a wide range fillet welding junction.
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Yukio MIYASHITA, Kosei OYAMA, Yuichi OTSUKA, Yoshiharu MUTOH, Hironori ...
Article type: Article
Session ID: J0402-2-5
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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Dissimilar materials spot welding between A5052 and PET (Polyethylene Terephthalate) has been carried out by using pulse YAG laser. Weldable conditions were obtained for PET/A5052 joint. Tensile-Shear test was conducted to evaluate strength of the joint. The maximum failure load in tensile-shear test was obtained for the joint welded with laser irradiation condition of 300V-20msec (65.5J). PET was observed in molten zone of A5052 in cross section of the welded region. Welded area increased with increase in heat input. Strength of joint was calculated apparently by failure load and welded area. The strength was almost constant regardless increasing of heat input in higher heat input conditions. However, in lower heat input conditions, the strength was not constant. Molten pool shape of A5052 changed with laser irradiation condition and that was not only depending on heat input. The difference in molten pool shape might affect on strength of the joint.
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Miki YAMAZAKI, Tomio IWASAKI, Shotaro HARA, Satoshi IZUMI, Sinsuke SAK ...
Article type: Article
Session ID: J0402-2-6
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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We experimentally investigated and reported the forces working at the contact interface between the metal and resin of a resin mold, which was made of metal cylinders covered with resin mold, in our previous paper. The forces were modeled by friction force, adhesion force, and contact pressure based on residual stress. A new coefficient for adhesion was introduced by describing adhesion force. Moreover, an FEM model of the forces acting on the contact interface was developed. To clarify the relation between the adhesion coefficient and the strength of adhesive bonding, we did atomic simulations of the shear deformation of metal and resin mold models, which we report in this paper. These results suggest that even if we do not examine elements, this technique can be used to determine adhesion coefficients by using atomic simulations.
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Masato NAKAJIMA, Hideo KOGUCI
Article type: Article
Session ID: J0402-2-7
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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A mismatch of different material properties in joints may cause stress singularities at the edge of the interface, which lead to the failure of the bonding part in structures. Therefore. it is important for the bonding strength of the joints to estimate three-dimensional stress sigularity at the vertex. In the present study, a boundary element method is used for evaluating the intensity of stress singularity. Model for analysis is composed of Si, resin and FR-4.5. Influence of the open angle from the side surface on the singular stress field at the vertex under an external load is investigated.
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Kenji Kaneko, Shumpei Takahashi, Asami Mizushima, Masatoshi Futakawa, ...
Article type: Article
Session ID: J0403-1-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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In this study, deformation behavior of Polypropylene is characterized by the inverse analysis based on load-depth curve measured by microindentation tests where a spherical indenter is used. By using Hertz's elastic contact low, the Young's Modulus can be calculated. Stress-strain curves are characterized for various strain rates as simple expressions. Then sophisticated inelastic constitutive equations can be decided on the basis of overstress model.
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Hideaki SAITO
Article type: Article
Session ID: J0403-1-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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Short fiber reinforced plastics by injection (FRP) are widely used as the mechanical part. However, theoretical study of deformation is lesser than experiment study of mechanical characteristic in a great deal of research. Since it is difficult to estimate deformation of FRP due to this anisotropy which is not constant. So, in this paper, I develop the expression for unidirectional deformation and whole Young's modulus on the assumption that this anisotropy is turning fiber orientation continuously in a different direction of width. And I analyse two type of fiber transition that one is the linear function and the other is circular function.
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Masayuki ARAI, X. H. Wu, Koji Fujimoto
Article type: Article
Session ID: J0403-1-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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A mechanism of inelastic deformation of freestanding plasma-sprayed thermal barrier coatings (TBCs) has been clarified. Cantilever-type bending tests are carried out inside SEM chamber in order to obtain a stress-strain curve of the freestanding ceramic coating peeled from the TBC coated sample by an electrochemical treatment and reveal the associated microstructure changes such as splats or splat boundaries. The bending test result indicated that the coating deforms with a nonlinear behavior under monotonic loading. In-flight particle velocity in the spraying parameter affected the stress-strain curve significantly. In-situ SEM observation during bending loading revealed that sliding at the boundaries between splats plays an important role in an inelastic deformation.
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Hiroyuki SEKI, Setsuo MIURA, Jun-ichi SHIBANO, Michiaki KOBAYASHI
Article type: Article
Session ID: J0403-1-4
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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The localization of plastic deformation is discussed as "stationary discontinuity" characterized by a vanishing velocity of an acceleration wave derived using the author's proposed theory of ultrasonic wave velocities propagating in plastically deformed solids. Therefore, based on the coincidence of the onset strains between localization and acceleration waves of vanishing velocity, the diagrams of diffuse necking, localized necking and forming limit are analyzed by applying the proposed acoustic tensor, which is based on the generalized Christoffel tensor derived by the author, and solving cut off conditions of the quasi-longitudinal wave to determine the onset strains of deformation localization. The purpose of the present paper is to analyze the effect of superimposed hydrostatic pressure on the localized deformation using the proposed theory.
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Setsuo MIURA, Michiaki KOBAYASHI, Junichi SHIBANO, Yoshiharu OZAKI, Yu ...
Article type: Article
Session ID: J0403-1-5
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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In the authors' previous studies, the estimation method about the amount of point defect development using the amount of intersected cross slip calculated by the finite element polycrystal model (FEPM) analysis was proposed. In this paper, the amount of point defects caused by biaxial plastic deformation of Aluminum under the change of strain paths is estimated by FEPM numerical simulations. The obtained result by FEPM analysis compared with the experimental results of localized deformation onset strain in an Aluminum specimen measured by laser speckle method. The simulation results were agreed well with the experimental results.
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Koichi TAKADA, Kazuhiko SAKAKI, Koichiro NAGATA, Daiki YUTOH, Yasuo SH ...
Article type: Article
Session ID: J0404-1-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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Coating adhesion is a critical factor in cold spray. Generally, particle impact velocity is a dominant factor of cold sprayed coating property, in addition, particle velocity heavily depend on spray angle. In this study, experiment was conducted to investigate the effect of spray angle, substrate hardness and surface roughness on copper coating adhesion strength and bonding morphology of individual copper particles. Spray angle is varied to six different levels: 30, 45, 50, 60, 75 and 90 degree. Used substrate materials are mirrored or blasted mild steel and aluminum alloy. The result shows that copper coating adhesion strength on mirrored steel substrate is increase with a decrease in spray angle. Deposition morphology of copper particles is vary depends on spray angle.
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Kazuhiro OGAWA, Tkahahiro NIKI
Article type: Article
Session ID: J0404-1-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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The cold spraying process, which has been studied as not only a new coating technology but also as a process for obtaining a thick deposition layer, is proposed as a potential repairing solution. The process results in little or no oxidation of the spray materials, so the surfaces stay clean, which in turn enables superior bonding. Since the operating temperature is relatively low, the particles do not melt and the shrinkage on cooling is very low. In this study, the cold spraying conditions were optimized by taking into account the particle kinetic energy and the rebound energy for application in repairing gas turbine blades. A high quality cold-sprayed layer is that which has lowest porosity; thus the spraying parameters were optimized to achieve low-porosity layer, which was verified by scanning electron microscopy (SEM).
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[in Japanese], [in Japanese]
Article type: Article
Session ID: J0404-1-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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Satoshi Onchi, Kazuhiro Ogawa, Momoji Kubo
Article type: Article
Session ID: J0404-1-4
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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One of the main factors of cold sprayed particle adhesion is anchor effect caused by plastic deformation. In this paper, the impact of Ni-base superalloy particle in cold spray using molecular dynamics (MD) method was described. This MD result was compared based on two parameters: (1) degree of plastic deformation, (2) average of number of atom binding at the interface of substrate and particle. As a result, it is thought that the possibility for the contribution of atom binding to adhesive strength between a particle and substrate. And first principle calculation was done to structures of Ni surface by replacing one Ni atom with a metal atom involved in IN738LC. This result shows which atoms in IN738LC contribute to the enhancement of adhesive strength of substrate/particle interface.
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M. FUKUMOTO, M. MASHIKO, M. YAMADA, E. YAMAGUCHI
Article type: Article
Session ID: J0404-2-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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Flattening and deposition behavior of an individual particle sprayed by cold spray was systematically investigated. Peripheral metal jetting in each particle was clearly observed with increase of process gas pressure. As the deposition efficiency of the particle simultaneously increased with increase of the gas pressure, appearance of metal jetting corresponded well to the deposition efficiency of the particle. From the practical viewpoint, deposition efficiency of the cold spray process can be effectively controlled with the jetting behavior in an individual sprayed particle.
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Kota SAITO, Kazuhiko SAKAKI, Kiyoaki TAKIZAWA
Article type: Article
Session ID: J0404-2-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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High velocity air fuel spraying (HVAF) is common process for deposition of coatings of various materials. Object to be sprayed is generally complicated shapes. Therefore, spray distance and spray angle are various. However, there is a few reports about it. In this study, it was aimed to clear the High-strength brass coating properties on L-shaped substrate. High-strength brass is good abrasion resistance and heat transfer. High-strength brass coating can be formed on L-shaped substrate. Vickers hardness at flat plate part is the same or more than bulk material and base powder. Although, in same spray angle at right angle part, Vickers hardness fall about 20% compared with flat plate part. From these results obtained, it seemed that high porosity cause of the flame jet changed by substrate shape.
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Takayuki KUWASHIMA, Tetsuya SONODA, Takashi SAITOH, Kazunori SUZUKI, M ...
Article type: Article
Session ID: J0404-2-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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Cold spray process is expected to apply to many industrial fields because the process has the feature with a little heat influence to spray material and gets the uniform coating without oxide in the coating. In this study influence of coating conditions and powder properties on coating properties were studied using low pressure type cold spray system manufactured by Inovati, USA. Aluminum and nickel powders were used as feedstock powders and they were sprayed on SUS304 stainless steel plate in various spray conditions. Particle velocity was measured by High Watch System manufactured by Oseir, Finland. Maximum particle velocity of aluminum using He gas as process gas was faster than using nitrogen gas. Deposit efficiency increases with increasing particle velocity. Although particle strength of nickel was bigger than aluminum one, maximum particle velocity of nickel and aluminum was almost the same. It was consider that the particle temperature affect of deposit efficiency.
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Kazunori SUZUKI, Maki FIJIWARA, Takayuki KUWASHIMA, Tetsuya SONODA, Ta ...
Article type: Article
Session ID: J0404-2-4
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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Cold spray deposition (CS) is a coating process by which coating can be produced by accelerating small solid particles to facilitate the deformation of particle upon impact, in an expanding gas stream in a converging-diverging de Laval type nozzle. CS applications will succeed in depositing of polymers, since without significant heating of the sprayed powder. The CS deposition by using PTFE powder was examined. However, the PTFE powder was not able to feed so that the powder was aggregate. In this report, the stabilization of the powder feed by the mixture of PTFE and inorganic material powders was examined. The powders mixed with PTFE and Al_2O_3 at a specific volume percentage stabilized the feed, and were able to form the PTFE film. The PTFE film that had been obtained by the CS method showed a super-water-repellency.
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Yoshiro SUZUKI, Akira TODOROKI, Kosuke TAKAHASHI, Yoshihiro MIZUTANI, ...
Article type: Article
Session ID: J0405-1-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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The present study employs the delamination detection in CFRP laminates using electrical resistance changes. Although the method detects the delamination without expensive sensors, the electrical resistance changes only due to electrode's damage make a wrong diagnosis. A delamination detection using statistical analysis of temperature characteristic of resistance changes is developed. CFRP laminates are heated up by applying electric currents through the electrodes mounted on the surface of the structure. When the delamination occurs, the electrical resistance change due to elevated temperature becomes different from that of the other intact parts. A statistical analysis method detects the change. The electrical resistance changes due to electrode's damage don't affect the temperature characteristic of resistance. The present study employs the new method for the delamination detection of cross-plied CFRP beams. In this study, the method is applied for quasi-isotropic CFRP plates. The detection limit of the method is investigated, and the effect of electrode's damage on the diagnosis is discussed.
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Kensuke SUZUKI, Akira TODOROKI, Yoshihiro MIZUTANI, Ryosuke MATSUZAKI
Article type: Article
Session ID: J0405-1-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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For Carbon Fiber Reinforced Plastic (CFRP), electrical conductivity of carbon fiber can be used as a sensor for damage detection. The change of electrical resistance of the CFRP structure has been studied as a self-sensing system for monitoring damages. Todoroki et al. reported that the electrical resistance change method successfully monitored various damages like matrix cracking, fiber breakage and delamination in CFRP laminates. To apply the electrical resistance change method to practical structures, reliability of the electrodes is a key issue. This paper contains the proposal of "Lead-Wire Integrated Electrodes" and the investigation of the reliability of the proposed electrodes under cyclic load. The electrodes were bonded to CFRP surface by using copper plating after polishing of the specimen surface with sandpaper to remove the surface resin. Lead-Wire was put on the electrode and bonded to the electrode by using copper plating. This proposed electrode is no initial defect. The specimen for this experiment was made of unidirectional CFRP prepreg. Volume fraction of specimens used for the fatigue test was almost 65%. Fatigue tests were carried out using a servo-hydraulic testing system. As a result, the electrodes had a fatigue life at the same level as the conventional strain gages under cyclic load.
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Keiji Fujibayashi, Yoji Okabe, Hideki Soejima
Article type: Article
Session ID: J0405-1-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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The authors developed a broadband Lamb wave propagation system using a macro fiber composite (MFC) actuator and fiber Bragg grating (FBG) sensors. One MFC is bonded on the top surface of a CFRP quasi-isotropic laminate with the thickness of 3.4mm and generates broadband Lamb waves in the range from 0Hz to 1200kHz. Then two FBGs bonded on the both surfaces of the laminate receive the propagated waves. By applying the wavelet transform to the superimposed waves or subtracted waves received in the two FBGs, we could identify S_0, S_1, A_0, and A_1 modes clearly. After that, an artificial delamination was induced in the laminate, and the waves were propagated through the delaminated area. As a result, the amplitudes of the S_1 and A_1 modes decreased with an increase in the delamination length, because the dispersion characteristic changes in the delaminated area due to the thickness change. Hence the delamination length was able to be evaluated from the amplitude ratios between the different order modes.
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Seiji KOBAYASHI, Ryosuke MATSUZAKI, Akira TODOROKI, Yoshihiro MIZUTANI
Article type: Article
Session ID: J0405-1-4
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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Since a fiber reinforced plastic structure is complicated in the adoption of integral molding for the reduction of structure weight, VaRTM (Vacuum assisted Resin Transfer Molding) is used widely for making a complicated structure easily. But local molding fault such as dryspot is liable to occur in VaRTM. To solve this problem, the impregnated area in the entire structure needs to be measured. In the present study, we measure the impregnated area using a smart film covering the entire structure. If a dryspot is likely to occur, the resin is heated by dielectric heating. Since the viscosity of resin is lower, the flow speed is faster. As a result, dielectric heating prevents a dryspot from occurring. Moreover, we confirmed the temperature of resin from measuring the frequency dependence of capacitance. We established the smart flow system of controlling impregnated are or temperature in VaRTM.
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Tsukasa KATSUMATA, Yoshihiro MIZUTANI, Akira TODOROKI, Ryosuke MATSUZA ...
Article type: Article
Session ID: J0405-1-5
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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One of the major fastening methods for the CFRP members used in aircrafts is bolted joint. CFRP bolted joints, although, have the problem that damages are occurred around bolt holes of CFRP, even by the tightening with low fastening force. As a result, the fastening force of conventional CFRP bolted joints is very low, and these strengths become decreased. In order to improve this weakness, configurations of the washers are changed in this study to increase the fastening force without CFRP damage, and thin sheet with high friction coefficient is sandwiched between CFRP members in this study to improve the friction force. In the validation testing, the failure strength of the proposal CFRP bolted joint become higher than normal CFRP bolted joints.
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Shinya HONDA, Yoshimasa OONISHI, Yoshihiro NARITA
Article type: Article
Session ID: J0405-1-6
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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Many natural materials, such as bones and trees, indicate non-homogenous anisotropy, and have higher performance than the homogenous one. To exploit those properties for design of artificial engineering structures, laminated composite shells reinforced by curvilinear fibers are analyzed to reveal their vibration and buckling properties. They have local anisotropy due to curved fibers, and show different properties from homogenous one. Projections of contour lines for cubic polynomial surfaces to the horizontal plane represent curvilinear fibers. This make is possible to represent multi-valued function and have large degree of freedom. The natural frequencies and critical buckling loads are calculated by using FEM, where the element coordinate system is translated to the tangential direction of the contour lines in the element centroids at each element. The results are given for a cylindrical shell and a shell with non-uniform curvature. It turns out that the curvilinear fibers have strong possibility to improve vibration and buckling performance of composite shell structures.
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Daichi WADA, Hideaki MURAYAMA, Kazuro KAGEYAMA, Kiyoshi UZAWA, Hirotak ...
Article type: Article
Session ID: J0405-2-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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The distributed strain sensing system with optical frequency domain reflectometry (OFDR) using fiber Bragg gratings (FBG) can measure distributed strain or temperature at an arbitrary position along an FBG with the high spatial resolution. As well as by the ordinary systems, however, strain measured by the sensing system can be influenced by the variation of temperature. In this study, we implemented simultaneous strain and temperature sensing by using PANDA (Polarization-maintaining AND Absorption-reducing) fiber. Through several experiments, we show that this sensing system can be applied to simultaneous distributed strain "and" temperature sensing.
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Naoki HIRAOKA, Ryosuke MATSUZAKI, Akira TODOROKI, Yoshihiro MIZUTANI
Article type: Article
Session ID: J0405-2-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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Intelligent tires are equipped with sensors to monitor strain, rolling radius and pressure of tire, and are expected to improve the reliability of tires and determine the road condition. However, the high stiffness of an attached sensor like a strain gauge causes debonding of sensors from tire rubber. In the present study, an optical method is used for the concurrent monitoring of in-plane strain and out-of-plane displacement (rolling radius) utilizing the non-planar surface of the monitoring object. The optical method enables noncontact measurement of strain. The in-plane strain and out-of-plane displacement are calculated by using image processing with an image of the interior surface of tire that is taken with a single camera fixed in tire. This new monitoring system is applied to commercial tire. As a result, the monitoring system is effective against concurrent monitoring of strain rolling radius. In addition, this monitoring system enables tire pressure monitoring.
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Yuya Nakazawa, Atsushi IWASAKI, Masataka YATOMI, Tadasi KIMURA
Article type: Article
Session ID: J0405-2-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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This research is about improvement of damage diagnostic accuracy of SI-F method under high noise condition. The SI-F method is statistical damage diagnostic method which diagnose existence of the damage from detecting the change of correlation between sensors as instead of change of single sensor measurement. Since the damage diagnosis is conducted by using parameter which shows change of correlation, this method has high tolerance to the noise and change of environments. However, deviation from a theoretical result occurs in the status under too high noise condition. Then in this paper, the noise condition evaluation parameter for SI-F method was proposed and the method for improvement of diagnostic accuracy using the parameter was confirmed.
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Atsushi IWASAKI, Akihiro MORIMOTO, Masataka YATOMI, Tadashi KIMURA
Article type: Article
Session ID: J0405-2-4
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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The present study is about an unsupervised damage diagnostic method for the structural health monitoring named as SI-F method. In the proposed method, structural condition is statistically evaluated by detecting the change of relation between measurement of several sensors. The relation between sensor measurements are identified by the response surface methodology. The change of the response surface is statistically investigated with the F-test. In this method, the correlation model and the noise of fluctuation of absolute value affect accuracy of diagnosis of structure. Present study conduct a evaluation of the effect of regression error and scale of noise for the diagnostic accuracy via the SI-F method by simulated data and performing fatigue crack monitoring test via the SI-F method. As the result, the minimum R^2_<adj> value, which required to evaluate the damage, was analytically indicated, and the effectiveness was clarified from application to an experimental result.
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Hiroshi ASANUMA, Jun KUNIKATA, Tatsushi KAIHO, Tetsuro YANASEKO
Article type: Article
Session ID: J0405-3-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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As sophisticated ceramics-based multifunctional materials are generally fragile, it is not easy to develop highly reliable multifunctional mechanical material systems by using them. In order to overcome this problem, Asanuma invented the "interphase forming/bonding (IF/B) method" to enable embedding them in aluminum-based materials as protective environments. Using the IF/B method, FBG sensors/aluminum composite and metal-core piezoelectric ceramic fibers/aluminum composite were successfully developed.
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Toshiyuki SUZUKI, Tadashige IKEDA, Tetsuhiko UEDA
Article type: Article
Session ID: J0405-3-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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A multi-modal piezoelectric ceramics composite (MMPC) is proposed, which can control bending and torsional deformations simultaneously. MMPC consists of piezoelectric ceramics, resin and electrodes. Electrodes are specially arranged so that both d33 and d15 effects of the piezoelectric ceramics can be driven simultaneously. The performances of MMPC as an actuator and a sensor are calculated by a finite element method and compared with those of PZT plate and Macro Fiber Composite. From the results, it is found that the proposed MMPC has a good feasibility as a multi-modal actuator and sensor.
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Takuji ITOH, Hiroshi OKUBO
Article type: Article
Session ID: J0405-3-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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In this study, a semi-active vibration suppression system comprising piezoelectric elements is developed for flexible structures. The vibration suppression system comprises a cantilevered beam with bimorph piezoelectric ceramic tiles shunted by a RL electrical circuit with a switching part. This study shows that the resonant shunt circuit functions as a type of a dynamic damper for mechanical systems and the proposed switching control, inspired by a sliding-mode control law, is more effective than the passive damping system especially for the multi-mode vibration suppression.
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Toru Inayoshi, Hiroshi Sugiyama, Yoji Okabe
Article type: Article
Session ID: J0405-3-4
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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We have developed a lightweight actuator beam with sufficient stiffness by bonding CFRP skins to an SMA honeycomb core with pre-shear strain and fixing both ends of the skins. When the beam was heated, the SMA honeycomb generated the recovery shear force and applied the force to the CFRP skins uniformly. Accordingly, this actuator beam was able to bend in the out-of-plane direction and generate bending force. In this research, in order to increase the actuation performance we investigated the relation of the pre-shear strain and the honeycomb shape to the bending deformation and force of the beam. As a result, when the larger pre-shear deformation was applied to the honeycomb, bending deformation and force were increased. Also, when the honeycomb shape was changed by addition of longitudinal SMA foils to decrease the cell size, the actuation performance was increased.
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Teiko Okazaki, Keita Aoyama, Kazimi Okada, Masayuki Yokoyama, Yasubumu ...
Article type: Article
Session ID: J0405-4-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
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To apply magnetostrictive alloy to force sensor, it is necessary that the alloy exhibits large magnetostriction, large coercive force and high strength. We have developed magnetostrictive (Fe-Ga-Al)-X-C (X=Zr, Nb, Mo) alloys which exhibited large magnetostriction (> 100 ppm) and high tensile stress (> 800 MPa). However, their coercive forces are small (< 10 Oe). In this study, we improved FeCo and Fe-Co-V alloys which have high Yung's modulus (170-205 GPa). Fe_<37>Co_<59>V_4 alloy exhibits large magnetostriction of 85ppm and coercive force of 30 Oe. Moreover, Fe_<36.5>Co_<52.5>V_<11> alloy has 58ppm and large coercive force of 60 Oe. It is found that magnetostriction is in inverse proportion to coercive force.
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