-
Tomohiro NARUSE
Article type: Article
Session ID: 2325
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
We developed a simplified model of a bolt jointed structure that uses shell and beam elements and takes into account the stiffness of the structure's jointed plates. The stiffness of an engineering structure with joints depends not only on the materials and dimensions of the structure but also on the stiffness of the fasteners that connect its components. To evaluate the mechanical behavior of a complex structure with many bolted joints using computer-aided engineering (CAE), it is necessary to develop a simple finite element (FE) modeling technique that accounts for the effect of joints on stiffness. In our technique, the stiffness of beam elements was calculated taking into consideration the stiffness of the jointed plates and bolts for each joint. We set an equivalent pressure area on the bearing surface region and, using constraint equations, connect the nodes in the equivalent pressure area to the beam element as rigid regions. We measured the eigenvalues of test pieces and calculated them for the same test pieces using FE analysis. The calculated eigenvalues agreed well with the experimental results, meaning that our model was accurate.
View full abstract
-
Chiaki SATO, Takashi INOUE, Tomoaki YAMADA
Article type: Article
Session ID: 2326
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Recently materials for car structures are gradually changing from steels to lighter ones such as aluminium alloys, polymer alloys and composite materials. To join such dissimilar materials, adhesively bonded joints are most promising. Mechanical fasteners including bolts or rivets are also used together with adhesives as hybrid joints in some cases. In this research, single lap joints of aluminium, Carbon Fiber Reinforced Plastics and steel adherends bonded with adhesives were used as specimens. Aluminium rivets and steel bolts are applied to the joints. As results of the research, it is found that applying rivets is not effective to increase the maximum load, and applying bolts is effective for not only the strength but also the absorbed energy.
View full abstract
-
Kenji KANEKO, Satoshi NARAHA, Kazuki ENOMOTO
Article type: Article
Session ID: 2327
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
-
MD. Rafiquzzaman, Yoshio ARAI
Article type: Article
Session ID: 2328
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
In this study, fracture mechanisms under monotonic and cyclic load and its stress distribution of an aluminum cast alloy locally reinforced by SiC particles and Al_2O_3 whiskers are investigated experimentally and numerically. The material is monotonically and cyclically deformed to failure at room temperature. The fracture origin and the fracture path are investigated on the fracture surfaces. The fracture occurs in the reinforced part under both monotonic and cyclic loads. The stress distributions around the boundary between the reinforced part and unreinforced part are calculated based on an inclusion array model considering the microscopic inhomogeneous effects. Both the experimental results and the finite element simulation results show that the critical location for fracture is changed by the external stress level.
View full abstract
-
Tetsuo Teramae, Yoshihiko TANAKA, Tomonori MATSUNAGA
Article type: Article
Session ID: 2329
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
SCC life estimation is very important to maintain the safety of nuclear power plants. One of the main research tasks in SCC life estimation is the evaluation of welding residual stress, which is the dominant stress causing SCC of nuclear power plants. Although some analytical research works have been conducted to clarify the welding residual stress, most of them are 2-dimensional analysis. In this paper, the authors report the residual stress of girth weld pipe obtained by axi-symmetrical and 3-dimensional numerical analyses, and these analytical results are compared with experimental residual stress measured by neutron diffraction method. It is concluded that the 3 dimensional analysis shows good correlation with the measured result. And, if the temperature history is well simulated, the difference of residual stress between aid-symmetric and 3 dimensional analyses is relatively small so that axi-symmetric analysis can be used for preliminary residual stress analysis.
View full abstract
-
Yukio MIYASHITA, Masahiro Koike, Hironori Tanaka, Katsuya Tokoro, Yosh ...
Article type: Article
Session ID: 2330
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Dissimilar metals welding between SUS304 and A5052 has been carried out by using a pulse YAG laser. Weldable conditions were obtained at spot diameter of 0.2mm. Shear - tensile test was conducted with the joints. Welding area increased with increase in heat input. However, the failure load did not increase with increasing of heat input, but the maximum failure load was obtained at a reasonable welding condition. According to the EDX analysis, intermetallic phase was formed at the interface of the joint. Formation of intermetallic phase was significantly observed for the joint welded with higher heat input and could strongly affects on the strength of the joint.
View full abstract
-
Toshiya NAKAMURA, Hirotaka IGAWA, Shunichi KOBAYASHI, Hideaki MURAYAMA ...
Article type: Article
Session ID: 2501
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Structural health monitoring (SHM) is an important and challenging technology to aim at the next generation of aerospace vehicles. The key issue is to determine the operational stress on real time which enables us to manage the structural integrity and air-worthiness. In our previous work, we reported the technique to identify distributed load, such as the aerodynamic load, by measurement data. This technique is based on an inverse interpolation method using results from a Finite Element Model (FEM). In this study, we evaluated the characteristics of this inverse analysis by the simulated model.
View full abstract
-
Gakuro AKIYAMA, Hidaki MURAYAMA, Kazuro KAGEYAMA, Isao OHSAWA, Kiyoshi ...
Article type: Article
Session ID: 2502
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
We have developed a new distributed strain measurement system with a long gauge Fiber Bragg Grating (FBG) sensor based on Optical Frequency Domain Reflectometry (OFDR). This sensing system enables us to measure strain at an arbitrary position along the FBG sensor with a high spatial resolution below 1mm. However, the sensing range of this system is confined to 〜10m at present. To expand the measurement range, we have problems in several components of the measurement system, such as the signal processing capability, limitation of measurable range due to reflection properties of the FBG sensor, and the effect of length fluctuation in the arm length of the interferometer. This paper discusses these factors using a simulation model of based on coupled mode theory. The signal analysis time was shortened by confining the analyzing section. The simulated result showed that, the measurable range is approximately 1.5m, and the length fluctuation in the arm length of measurement interferometer has a significant effect on the measured result.
View full abstract
-
Takashi YARI, Kanehiro NAGAI, Kazuo Hotate, Kwang-Yong Song, Tateo Sak ...
Article type: Article
Session ID: 2503
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Structural health monitoring (SHM) system using optical fiber sensor is powerful solution to reduced maintenance cost and structural weight. Especially, in order to monitor large area structural health monitoring, the Brillion optical correlation domain analysis (BOCDA) method is most compatible method because of its long-range measurement, high spatial resolution, and high-speed strain sampling. In this paper, the authors report subcomponents test result, which is distribution strain measurement with 4.5mm spatial resolution BOCDA system. The test article is simulate airplane critical structural portion such as weight-lightened portion and bolted joint portion. The stress concentration and missing bolts can be detected with high spatial resolution BOCDA by strain distribution change.
View full abstract
-
Kohei OHARA, Hideaki MURAYAMA, Kazuro KAGEYAMA, Isao OSAWA, Kiyoshi UZ ...
Article type: Article
Session ID: 2504
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Distributed strain sensor with particularly high spatial resolution is required for assessing integrity of welded joint by monitoring its strain distribution. A distributed strain measurement system based on optical frequency domain reflectometry (OFDR) can measure a strain at arbitrary position along a long gauge FBGs (fiber Bragg grating) with high spatial resolution less than 1mm. In this study, we evaluated the applicability of the system to strain monitoring of welded joints in static tensile tests. We could successfully measure the strain distribution along the weld line for 100mm, and could show the process of degradation of the specimen. In addition, we could observe that the strain distribution sharply fluctuates with acoustic emissions in the area where anomalous distortions in the strain distribution were observed under the relatively lower load. We could also measure strain distribution ranged over 8000με within the FBG with gauge length of 100mm. The measured strain was mare than -10000με at maximum. Thus, the system was proved to have excellent spatial resolution and the measurement range sufficient to monitor the strain distribution of the welded joints.
View full abstract
-
Katsuhiko OSAKA, Ken KAKU, Tatsuro KOSAKA, Yoshihiro SAWADA
Article type: Article
Session ID: 2505
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
In the present study, a health monitoring system for adhesively bonded FRP joints was investigated which used a Michelson optical fiber interferometer. In this system, the sensors with different gage lengths are embedded into the FRP adherend at the end of bonded part and measure the strains in that part. Single lap joint specimens were used whose adherends were an aluminum alloy plate a GFRP laminate including the Michelson sensors. Under tensile loading, the ability of strain measurement at the bonded part was examined for the monitoring system devised in this study. Strain analysis by FEM was also performed to compare the calculated strain distributions and the strain outputs from the Michelson sensors. The results in this study showed that the present monitoring system had the ability to measure the strain distribution at the end of the bonded part in the FRP bonded joints and for their health monitoring.
View full abstract
-
Zhiwen ZHANG, Zhongwei JIANG, Kazuya SONODA
Article type: Article
Session ID: 2506
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
This paper present a study on detection and evaluation method for monitoring joint of truss structure by measuring the impedance change of piezoelectric patches which were glued on the structure. The structure joint used in this study consists of two aluminium beams connected by bolts. The damage is simulated by dropout the bolts. The detection and evaluation method using bending vibration driven by single piezoelectric patch is proposed. In order to estimate the damage condition, the damage assessment index waveform change ratio r is used in this paper. Moreover, the effects of the weight and vibration act on the joint for damage detection and evaluation are investigated experimentally. Experimental results show the detection and evaluation method proposed in this work are validated for assessment of the dropout of bolts.
View full abstract
-
A. IWASAKI, A. TODOROKI, Y. SHIMAMURA
Article type: Article
Session ID: 2507
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
This research is about a statistical diagnostic method for the structural health monitoring which is applicable to existing structures from the present moment. In this method, structural condition is statistically diagnosed by the change of the response surface. The response surface is a regression model of sensor's outputs. The change of the response surface is statistically tested with the F-test. In the F-test, a threshold of normal or fault condition is simply investigated with a theoretical F-probability distribution. Therefore, this diagnostic method only requires data of intact condition and does not require the complicated modeling and information of fault condition. Since the SI-F method is able to detect the damage in the structure by judging the deviation from the normal state, it is important to avoid the false positive detection for raising the reliability of the structure. In the present study, relationship between the condition of the false positive detection and the shape of the response surface is clarified. And several numerical simulations were carried out to declare the optimal condition of the damage detection for the structural health monitoring using the SI-F method.
View full abstract
-
Mamoru SAITO, Katsuhisa KITAGUCHI
Article type: Article
Session ID: 2508
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
This paper presents an appearance-based method for object pose estimation using single camera image. Canonical Correlation Analysis is introduced to build a compact appearance model and use it for pose estimation. In the approach, we first obtain a pair of training data set, i.e., object images and their pose parameters. The appearance model is given as the subspace spanned by the canonical vectors that maximize the correlation between images and poses. Pose parameters of currently observed image is predicted by finding the regression coefficient in this subspace. We also introduce the kernel methods to cope with the non-linearity lies in training data set. In the experiment, we have examined the applicability of our method for vehicle type classification using the images taken by a road monitoring camera. Pose performance of CCA and KCCA models is discussed through the experimental results.
View full abstract
-
Nozomi Akino, Shu Minakuchi, Tadahito Mizutani, Nobuo Takada
Article type: Article
Session ID: 2509
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Impacts create internal damage in foam core sandwich structures and this internal damage can cause severe reduction in strength. Therefore, the aim of this study is the impact identification of foam core sandwich panels by using embedded fiber Bragg grating (FBG) sensors. FBG sensors were embedded between the skin-core interface and strain response during impact was used to identify the impact location. Strain measurement system consists of a light source, FBG sensors, arrayed waveguide grating (AWG) and photo detectors. The accuracy of the system was demonstrated by indentation test using form core sandwich panels with FBG sensors. From the result, this system was able to measure strain accurately. And then we investigated the relation between strain and distance from sensors to the indentation point.
View full abstract
-
Masahiro SAITOH, Tadahito MIZUTANI, Nobuo TAKEDA
Article type: Article
Session ID: 2510
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The temperature-compensated strain measurement was demonstrated for the CFRP cure process monitoring by the parallel use of two fiber optic measurement technique. One is pulse-prepump Brillouin optical time domain analysis (PPP-BOTDA) system, and the other is fibber Bragg grating (FBG) sensor. Both PPP-BOTDA and FBG sensor system can acquire an axial strain and the temperature change as the center frequency change and the center wavelength change by means of the spectrum shifting. For accurate distributed residual strain measurement of the embedded optical fiber by PPP-BOTDA systems, it is necessary to compensate the influence of the temperature change in the cure process. In this study, a novel temperature compensation method was applied by using the difference in strain and temperature sensitivity between PPP-BOTDA and FBG system.
View full abstract
-
Tatsuro KOSAKA, Yoshiyuki MINAMI, Katsuhiko OSAKA, Yoshihiro SAWADA
Article type: Article
Session ID: 2511
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
An AFP molding method using UV-curable prepreg tapes has been recently studied. In order to optimize the molding method, it is essential to know the relationship between the degree of cure and UV dose near the exposed surface. A cure monitoring by a Raman spectroscopy is suited for the purpose. In the present paper, the cure monitoring method has been applied to UV-cured polymers with a UV LED, which is very useful as the spotlight of the UV-AFP molding method due to the small size, light weight and high power. The Raman peak of a carbon-carbon double bond was used to estimate the degree of cure. From the experimental results, it appeared that the degree of cure was controllable by total UV dose when the UV LED was used, while the more power is necessary to cure the polymers comparing to the UV light.
View full abstract
-
Hiroyuki OHTA, Hiromi SHIMAZU, Yohei TANNO
Article type: Article
Session ID: 2512
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
A low power strain sensor chip, which contains a strain sensitive device and an amplifier circuit on single-crystalline silicon, was developed using the semiconductor fabrication process. The piezoresistance effect was adopted to measure strain change, and a Wheatstone bridge circuit, which consists of piezoresistors along the <110> directions, was formed on the silicon chip to detect the strain. The amplifier circuit has special functions, such as magnification change and zero adjustment functions from the exterior of the chip for optimizing the strain measuring operation. The experimental results showed that the sensor chip had outstanding features, which are high strain sensitivity (gage factor 4800), low power consumption (2.3mW). Considering these features, the sensor chip is ideal for strain monitoring system of mechanical materials.
View full abstract
-
Junich Koyama, Ming Yang
Article type: Article
Session ID: 2513
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Micro-sensor which embedded in die was fabricated by using semiconductor processing technology. Follow a previous report, we applied the sensing system to V-bending process and we performed a trial to estimate bending angle with this system. In this paper, we optimized the shape of the die and the shape of the sensor tip and the placement to get the strain correct information from the die shoulder during processing. And by converting the strain information from a sensor into the strain ratio, we showed possibility to be able to treat as the information that was hard to be influenced by a change of the load.
View full abstract
-
Ryosuke MATSUZAKI, Akira TODOROKI
Article type: Article
Session ID: 2514
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Measurement of strain of tires in-service is effective to improve reliability of tires and ABS system. Since conventional strain gages have high stiffness and require lead wires, the conventional strain gages are cumbersome for the strain measurement of the tires. The backgrounds require a new low cost wireless sensor for tires. In the present study, a new flexible patch-type strain sensor utilizing electric capacitance change is proposed and analytically investigated. The sensor is made from flexible polyimide substrates and ultra-flexible epoxy resin, which makes the sensor low in stiffness and high in elongation as a whole structure. The sensor utilizes capacitance changes due to the applied strain. The sensor is applied to an automobile tire, and compression tests are performed.
View full abstract
-
Yasubumi FURUYA, Tadashi MITUHASHI, Kenji HASHIMOTO, Teiko OKAZAKI, Ch ...
Article type: Article
Session ID: 2515
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
A torque sensing system by using the magnetostrictive ring of FeGa (Galfenol) alloy was developed and magnetic flux leakage from the ring attached on the rotating shaft was experimentally measured. The ring material is the new Galfenol system (FeGaAlC) alloy with higher strength and ductility. The influence of alloy compositions (SK-105 carbon steel, FeGaAlC alloy), rotations speed(250〜1000rpm) on the sensitivity of pick-up voltage from Hall sensor was discussed. As a result, the sensitivity in FeGaAl-C alloy increased by about six times at rotations speed 250rpm in comparison with SK-105, and an almost linear relationship between pick-up voltage and applied toque value was obtained.
View full abstract
-
Toshiya TAKAHASHI, Kenji HASHIMOTO, Teiko OKAZAKI, Takeshi KUBOTA, Chi ...
Article type: Article
Session ID: 2516
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The purpose of this study is to improve the strength as well as magnetic property of a magnetostr ictive FeGaAl (Galfenol) system alloy. Rapid solidification ribbon samples of two kinds of kinds of Fe79.5Ga15.6Al4.9 [at.%] alloy and the (Fe80Ga15Al5)98.4C1.6 [at. %] alloy. Were produced using the nozzleless twin rolling method. In addition, material imp rovement by heat treatment in the characteristic, (Fe80Ga15Al5)98.4C1.6 [at.%] ribbon was studied. A maximum magnetostriction and tensile strength is 210ppm and 638MPa respectively in the Fe79.5Ga15.6Al4.9 [at.%] alloy and these are 175ppm and 959MPa in (Fe80Ga15Al5)98.4C1.6 [at.%] alloy by annealing at 823K for 3.6ks, which seems very useful in the industrial application because of the high tensile strength of nearly 1GPa in the of FeGaAl-Calloy.
View full abstract
-
Yoshio TAIRA, Ryo NAKANO, Syun SASOU, Yoshihito MATSUMURA, Yoshitake N ...
Article type: Article
Session ID: 2517
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Influences of electron beam (EB) irradiation on magnetostriction and its susceptibility of Fe_<2.6>Sm alloy thin films have been investigated. The alloy thin film deposited on a (100) plane of silicon wafer is prepared by using direct current magnetron sputtering apparatus. The irradiation enhances compressive magnetostriction and its susceptibility. The enhancement of magnetostriction is caused by decreasing in the volume fraction of low magnetostrictive crystalline phase, resulting in generating the large magnetostriction. The high susceptibility is explained by randomization, induced by EB-irradiation, of Fe_<2.6>Sm amorphous sample, which is easy to rotate the magnetic moment.
View full abstract
-
Hiroshi Sato, Yoshiro Shimojo, Nobuo Sakamoto
Article type: Article
Session ID: 2518
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The shape-memory alloy, for example NiTi (Nickel Titanium), is used for an actuator and frame by the shape-memory effect and the super-elasticity effect. And piezoelectric material, for example PZT (Lead Zirconate Titanate), is used for an actuator and sensor by the piezoelectric effect and the pyroelectric effect. However, each of the materials has been used for the sensor and the actuator independently because the principle of the function of each of materials is different. In this research, a new multifunctional device combines these four functions is developed by coating the PZT thin filmof 20μm to the surface of the NiTi wire by the chemical reaction by using the hydrothermal crystallization method. We succeeded in the detection of the displacement at a super-elastic deformation of this multi functional device from the piezoelectric effect of the PZT film on the surface. By combining each effects, the multifunctional device can be used for a self-sensing actuator, wherein the transformation by the shape-memory effect is detected by the piezoelectric effect or the pyroelectric effect, and the rough and precision actuator performs the rough movement by the shape memory effect and performs the precise movement by the piezoelectric effect.
View full abstract
-
Hiroshi ASANUMA, Takamitsu CHIBA, Naohiro TAKEDA, Hiroshi SATO
Article type: Article
Session ID: 2519
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
This paper describes comparison of output voltages generated from the metal core piezoelectric ceramic fibers embedded in various matrix materials, that is, aluminum, CFRP (Carbon Fiber Reinforced Plastic) and epoxy resin. The piezoelectric ceramic fiber/aluminum composite was fabricated by the interphase forming/bonding method, and the piezoelectric ceramic fiber/CFRP composite was fabricated by hot pressing. In the case of epoxy resin matrix specimen, the fiber was coated with silver paste to form outside electrode and embedded in the resin. Oscillation tests were carried out to compare aluminum matrix and CFRP matrix and impact tests were carried out to compare aluminum and epoxy matrix. As the results, it was found that the aluminum matrix composites have better response and lower voltages than the other two.
View full abstract
-
Chinori Iio, Shigeru Inaba, Toru Watanabe, Kazuto Seto
Article type: Article
Session ID: 2520
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
In this paper we propose a semi-active vibration control method for multiple high-rise buildings arranged in parallel. Using this method, it is possible to control vibrations of high-rise buildings against strong winds and large earthquakes. In this study, two model buildings are connected with hybrid MR (Magneto-Rheological) dampers. The objective of this research is to control the first and second bending modes of each building using this method. The control effect is evaluated by exciting the base of the structures by time response and measuring the frequency response of the structures. Simulation results show that fairly good control performance has been achieved by this method.
View full abstract
-
Yohsuke TOMITA, Takumi SASAKI, Noboru SUGIMOTO
Article type: Article
Session ID: 2521
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
This study deals with the semi-active isolation system using magnetic fluid. This technology provides abilities that vibration of earthquake doesn't transfer to buildings with isolation layer between buildings and ground. In this study, we use FFF, which we proposed in the previous report, for isolation system. This system is semi-active system. First, insulation and restoring performance of this system are investigated. Next, we try to model this system as a frictional vibration model, since acceleration of upper structure showed like frictional vibration response when sine vibration wave is inputted to the experimental model. And we executed numerical simulation of modeled system. In this report, we confirmed the effectiveness of this system against the sine vibration wave and earthquake wave.
View full abstract
-
Yoshimi Watanabe, Yuji Furuya, Hisashi Sato, Yoichi Nishino, Ick-Soo K ...
Article type: Article
Session ID: 2522
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
High damping alloys are drawing strong attention for engineering applications because of the increasing demand for vibration and noise reduction in various fields. The Fe-Mn based alloys undergoing fcc (γ) to hcp (ε) martensitic transformation are known as low cost high damping alloys, as well as good shape memory alloys. It is reported that the damping sources of Fe-Mn alloys are boundaries of several types closely related to ε-martensite and γ-austenite, such as stacking fault boundary in ε-martensite and γ-austenite, γ/ε-interface, and ε-martensite variant boundary. On our previous study, the training effect in Fe-Mn-Si shape-memory alloys had been examined, and it was found that the training effect originates mainly from development of the homogeneous and fine deformation structure by the thermal cycling. With the above in mind, in this study, the influence of training effect on damping capacity in Fe-20mass%Mn alloy is examined. It is found that the superior damping capacity and mechanical property were obtained for the Fe-Mn alloy by the thermal cycling.
View full abstract
-
Yasufumi WATANABE, Hiroshi OKUBO
Article type: Article
Session ID: 2523
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
This paper propose a actuator method of sound-induced vibration control and noise isolation by using a piezo-electric devices-In this research, a hardware experiment has been made for investigate the effectiveness of the proposed controller. The control system is designed by using a mixed H2/H ∞ control, where the weighting functions in frequency domain are designed considering the dynamic characteristics of the smart board.
View full abstract
-
Keisuke KUMAGAI, Akira TODOROKI, Ryosuke MATSUZAKI
Article type: Article
Session ID: 2524
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
For Unmanned Aerial Vehicles (UAV), "Morphing wing" is desired to reduce the total weight of structures and improve the maneuverability. Morphing wing is defined as an aircraft wing or structure that can change shape during flight. It enables the aircraft to change its standard performance. In this study, a new Partially-Flexible CFRP (PFC) is proposed for the material of morphing wing. The PFC consists of two kinds of matrices: high-stiffness matrices and low-stiffness matrices in a structure. Sealant is adapted to the low-stiffness matrices, and epoxy resin is used for the stiff structural matrices. These matrices have good adhesive properties with each other. Reinforced fiber continues in the whole structure, so the PFC has enough strength to be applied to UAV. In this paper MacKibben Artificial Muscle Actuators is made of silicone tube and MT sleeve and the actuators are applied to the PFC specimen.
View full abstract
-
Tsutomu OIKAWA, Haru-Hisa Uchida, Yoshitake NISHI
Article type: Article
Session ID: 2525
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Hydrogenation operated unimorph device composed of LaNi_5 hydrogen storage alloy film with palladium over-layer has been successfully developed, when both film and layer are deposited on a carbon fiber reinforced polymer (CFRP) substrate. As a result, the bending motion after 1000s, palladium coated LaNi_5 alloy film with the CFRP supporting sheet exhibits the large displacement, which is larger than that of the platinum coated LaNi_5 hydrogen storage alloy film deposited on CFRP.
View full abstract
-
Hiroshi ASANUMA
Article type: Article
Session ID: 2526
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Two typical examples of the multifunctional mechanical material systems classified into two types due to innovative processing and designing concept are introduced in this study. As the Type I material system, that is, a composite of a fragile functional material and a reliable metal matrix, the metal-cae piezoelectric ceramic (PZT) fiber/aluminum composite was successfully fabricated by the interphase forming/bonding method without fracture, and its sensing capability of vibration was clarified. As the Type II material system, that is, a composite of competitive mechanical materials, of which common properties are maintained and the other dissimilar properties conflict with each other and generate functions, the CFRP/aluminum active laminate was selected. Its high performance type was fabricated by sandwiching a sheet of elastomer between two conventional and single active laminates, and it was found that it doubled the output force of the single active laminate without sacrifice of its actuation capability.
View full abstract
-
Hiroshi ASAMUMA, Yuta ADACHI, Toshiyuki NAKATA
Article type: Article
Session ID: 2527
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
This paper describes fabrication and evaluation of an active laminate having hollow channels to develop new functions such as cooling and healing. It was made by hot-pressing of an aluminum plate as a high CTE material, a unidirectional CFRP prepreg as a low CTE material and an electric resistance heater, a unidirectional GFRP prepreg as an insulator between them and copper foils as electrodes. Hollow channels were formed in the GFRP layer. Hot pressing condition was selected by experiments to shorten the time necessary to make its shape stable. The curvature of the active laminate having the hollow channels decreased with increasing volume fraction up to 0.75. The number of them was changed from 1 to 12 at a constant volume fraction of 0.3, but it didn't affect the curvature.
View full abstract
-
Toshiyuki NAKATA, Hiroshi ASANUMA
Article type: Article
Session ID: 2528
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
This paper describes fabrication and characterization of high performance, that is, large deformation and high output force type active laminate using elastomer. The conventional and single active laminate was made by hot-pressing of an aluminum plate as a high CTE material, a unidirectional CFRP prepreg as a low CTE/electric resistance heating material and an epoxy adhesive film as an insulating material. The high performance type active laminate was made by sandwiching a sheet of elastomer between two conventional and single active laminates. The effect of hardness and partial removal of the elastomer on their shape, deformation and output force characteristics were investigated. It was found that the high performance type active laminate doubled the output force of the single active laminate without reducing its actuation capability by laminating a sheet of elastomer of which hardness is very soft or which is partially removed between two conventional and single active laminates.
View full abstract
-
K. Mizuuchi, K. Inoue, M. Sugioka, M. Itami, K. Ozaki, K. Hamada, H. A ...
Article type: Article
Session ID: 2529
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Boron fiber reinforced Ti matrix composites were fabricated by pulsed current hot pressing (PCHP) process at various processing conditions at a pressure of 32MPa in vacuum of 2Pa. Good bonding between the fiber and matrix was obtained by PCHP at 1123K for less than 450s. When fabricated at the holding temperature higher than 1173K, TiB_2 layer was formed along the interface between the fiber and matrix, and the crystallization of boron in the vicinity of tungsten core in the fiber occurred. The thickness of TiB2 layer formed and the crystallized boron increased with increasing the holding temperature. Tensile tests were carried out at room temperature for the composites fabricated by PCHP at 1073K. Tensile strength of the composites containing 17.2vol.% boron fiber attained at 706MPa. This value was about 80% of the tensile strength calculated by the force equilibrium equation of a composite along with the fiber axis direction.
View full abstract
-
Tatsushi KAIHO, Kiyotada KATO, Takamitsu CHIBA, Hiroshi ASANUMA
Article type: Article
Session ID: 2530
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
This paper describes development of the SiC fiber/Al active composite having shape recovery function and its application. The results obtained are as follows: (1) The shape of the SiC fiber/Al active composite can be recovered by heat-treatment even after severe plastic deformation. (2) The continuous and discontinuous SiC fiber/Al type active composite can be easily fabricated by combination of breaking pre-notched SiC fibers in the matrix by bending and heat treatment to remove the plastic deformation caused by the bending.
View full abstract
-
S. Kishimoto
Article type: Article
Session ID: 2531
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
A metallic closed cellular material containing ceramics has been fabricated. Ceramics particles and porous ceramics particles coated with nickel-phosphorus alloy layer using electro-less plating were pressed into the green pellets and sintered at high temperatures in a vacuum condition. These particles were also sintered by a spark plasma sintering method. Metallic closed cellular materials containing ceramics were then fabricated. The three points bending tests were carried out to measure the mechanical properties of these materials. Damping properties and physical properties were also measured. The results showed that these metallic closed cellular materials have different strength and different internal frictions among the specimens that containing different ceramics.
View full abstract
-
Noriyoshi Miwa, Mitsuru Hirano, Yoshitake Nishi
Article type: Article
Session ID: 2532
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Airplanes are dream worthy mover machines. Titanium and its alloy have been applied for air-compressor at the front of jet engine cover. On the other hand, carbon fiber reinforced polymer (CFRP) has recently applied for not only wing, but also fan breads of new turbo fan engines. To prevent impact force, leading edge of titanium is often mounted on the CFRP fan breads by adhesive. It is difficult to weld the bread. In order to enhance the joining strength, a carbon fiber reinforced interface has been suggested. To prevent to decay the carbon fiber felt by reaction to metal matrix, the fiber has been coated with nickel film, which protects the carbon fiber against titanium liquid. One side plain of the coated fiber felt is dipped into titanium liquid. After solidification, another side of the coated felt is also dipped in the polymer. The nickel coated carbon fiber reinforced interface between CFRM and CFRP probably acts as one of ideal joining methods.
View full abstract
-
Daiji KUBO, Keisuke IWATA, Keisuke TAKADA, Akira TONEGAWA, Yoshitake N ...
Article type: Article
Session ID: 2533
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Influences of electron beam irradiation on interface strength were studied for metal thin film. A measurement method to measure the interface vertical to thin film plain on substrate has been suggested. Metal thin films were prepared by DC magnetron sputtering process. To obtain the elasticity, tensile strength and its strain of the interface strength, the stress-strain curves were obtained at joining interface vertical to the thin film plain on the substrate. Interface strength values of metal thin films prepared by different processes were obtained.
View full abstract
-
Yutaka MATSUI, Noboru SHINKE, Masanori TAKUMA
Article type: Article
Session ID: 2534
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
In this study, we applied the concept of smart structures/materials to the alumina (Al_2O_3) ceramics and granted them the self crack detection, the crack growth control and the crack-healing abilities. And the four-point bending test was carried out in them. In this smart system, the AE sensor detects the crack growth, the SMA controls it and the YAG laser irradiation heals the crack on the surface of specimen. In order to evaluate the crack growth control and the crack-healing abilities, the pre-cracked specimens in which the cracks were generated by the Vickers indenter were prepared. The YAG laser irradiation during the bending test showed the crack-healing effect, and the specimen recovered the bending strength 36% than the pre-cracked specimen. And the SMA decreased the cumulative AE events 30% than no-suppressed specimen.
View full abstract
-
Young-Soon JUNG, Wataru NAKAO, Koji TAKAHASHI, Kotoji ANDO, Sinji SAIT ...
Article type: Article
Session ID: 2535
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The crack-healing behavior of the machined cracks in Si_3N_4/20wt% SiC composite was investigated. The addictive powders are used the 5wt.%-Y_2O_3+3wt.%-Al_2O_3. The machined cracks were introduced by the machining, during make a semicircular groove on the center of specimen. The machined specimens were healed in various temperatures and time in air. The optimized crack-healing conditions were found to be temperature of 1300℃ and time of 1h, because the machined specimen healed under this condition exhibited almost same strength as the smooth specimen healed. Moreover, the high-temperatures strengths (<1300℃) exhibited similar properties to the Vickers indented crack-healed specimen. It can be demonstrated that the crack-healing was useful for an increase in the strength of the machined ceramics, economically.
View full abstract
-
Masato Ono, Wataru Nakao, Koji Takahashi, Kotoji Ando
Article type: Article
Session ID: 2536
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Alumina is used in various fields as a machined component. However it has a weakness in low fracture toughness. Thus, countless cracks may be initiated randomly by machining, and the cracks decrease the component's mechanical properties and reliability. To overcome this problem, crack-healing ability could be a very useful technology. In this study, Al_2O_3/SiC particle composite was sintered. This alumina exhibits excellent crack-healing ability. Small specimens for bending were made from the Al_2O_3/SiC. A semicircular groove was machined hardly using diamond ball-drill. The local fracture stress was reduced from approximately 820MPa to 300MPa by machining. The machined specimens were crack-healed under various conditions. The fracture stress of these specimens after crack-healing was evaluated systematically at R.T. It was found that the local fracture stress of the machined specimen recovered almost completely by crack-healing. Therefore, it was concluded that crack-healing could be an effective method for improving the structural integrity of machined alumina while reducing machining costs.
View full abstract
-
Wataru NAKAO, Takehiro TOYODA, Kotoji ANDO
Article type: Article
Session ID: 2537
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The effect of self-crack-healing on the thermal shock resistance of structural ceramics was investigated. Mullite containing 15vol.% SiC particles composite which has excellent self-crack-healing ability was used for the present study. The strength for thermal shock at the vicinity of the healed crack was superior to that of the base material. From the effect and the elimination of surface cracks which cause the stress concentration due to the generated thermal stress, crack-healing treatment improved the thermal shock resistance of the mullite/SiC composite. Furthermore, surface cracks introduced by the thermal shock could be healed.
View full abstract
-
Kinji Asaka, Ichirou Takeuchi, Ken Mukai, Kenji Kiyohara, Takushi Sugi ...
Article type: Article
Session ID: 2538
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
We have reported a novel low-voltage driven dry polymer actuators based on single-walled carbon nanotube gels (bucky gels) of ionic liquids. The actuator has a bimorph structure composed of polymer-supported bucky gel electrodes and a polymer-supported ionic-gel electrolyte. In order to improve the performance of the actuator, we further explored the preparation method of the bucy-gel electrode and internal ionic liquid species. Herein we report details of improved response of our bucky gel actuator.
View full abstract
-
Takayuki TAO, Takenobu SAKAI, Satoshi SOMIYA
Article type: Article
Session ID: 2539
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Shape Memory polymer (SMP) is known to have visco-elastic behavior. Shape recovery is considered to occur due to this visco-elastic behavior. On the other hand, creep and creep recovery may also occur that is known as one of visco-elastic behavior. It is important to understand creep and creep recovery behavior, because it effects on material's shape memory and shape recovery characteristics. This research examined the creep and creep recovery behavior by three point bending creep test. As a result, time and temperature dependence was confirmed, and also master curve can be drawn by superposing the creep compliance curves. Moreover, estimation of creep and creep recovery can be possible by master curve, shift factor and Boltzmann's superposition principle.
View full abstract
-
Yaoyang ZHENG, Kunio SHIMADA
Article type: Article
Session ID: 2540
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Shimada laboratory has been developed the MCF electric conductive rubber, combining the MCF in a silicon-oil rubber a few years ago. Recently, by the use of the MCF electric conductive rubber, we are developing a haptic sensor for the applications to a robotic finger, artificial skin, and so on. For the purpose of the applications, it is important to understand various characteristics of the MCF electric conductive rubber, for example, electric resistance. In this research, at first, we investigated the characteristics of its electric resistance when the MCF rubber is compressed to have a deformation. Secondly, we have made many experiments and pointed out test results though stress-strain diagram.
View full abstract
-
Mutsumi KANEKO, Takayoshi YAGASAKI, Ichiro TAKANO, Yuji KIMURA, Takash ...
Article type: Article
Session ID: 2541
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
From previous study, we tried that formed various metal thin films on the surface of biodegradability resin with ion beam, and performed mult-functionalization. In the place, we decided to perform this study for the purpose of giving Amorphous Carbon thin film instead of existing metal film from a point of view to realize environmentally-friendly materials. In addition, when the biodegradability resin system which gave amorphous carbon thin film come true, because end processing is easy, naturally, this materials system makes it possible to apply in vivo. Amorphous carbon can plan functionalization by giving it to biodegradability plastic and some macromolecule materials, for may have various characteristics by adjusting structure. In this study, we try to given amorphous carbon thin film by ion beam assist method and surface carbonization by ion implantation method, besides perform analysis of an amorphous carbon thin film. Furthermore, we carried out structure analysis and evaluated function of thin film after through forming.
View full abstract
-
Hiroyuki MIKI, Yutaro HOSHI, Takanori TAKENO, Toshifumi SUGAWARA, Tosh ...
Article type: Article
Session ID: 2542
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Diamond-like carbon film is a kind of hard coating layers which consists of hydrogen, carbon, and oxygen If the condition of the carbon bond and the content of the hydrogen change, the physical properties of a diamond-like carbon film become different It is also well known as a material with the excellent mechanical properties, such as low friction, higher hardness, and high biocompatibility. New features in addition to the good mechanical properties may appear in the diamond-like carbon films containing metals. Metal addition newly gives electrical conductivity in the film, though the film without metals is originally an insulator. Furthermore, the changing characteristic of the electrical resistance by external factors, such as a temperature, an external magnetic field, and a pressure, can be given. The usage of a diamond-like carbon film with the new functionality which was not in the conventional coating material maybe expected. We have already proposed a coated type thin film sensor as one of the applications of an amorphous hydrogenation carbon thin film with new functionality. In this paper, we report the new functionality (magnetic property, electrical property, etc.) of the diamond-like carbon film which contains transition metals as an additional element.
View full abstract
-
Achariya RAKNGARM, Hiroki SUNOHARA, Yoshiharu MUTOH
Article type: Article
Session ID: 2814
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The commercially pure Ti (cp-Ti) were blasted with Al_2O_3 grit blasting and HAp/Ti mixed powders at room temperature using sand and wet blasting machine. Then plasma spraying with Ti powder or HAp/Ti mixed powder was carried out as bond coat layers. The hydroxyapatite top coat was sprayed with 100μm thickness, subsequently. The cross-sectional observations of those coating layers exhibited unclear interface region between two coating layers. The XRD patterns of the as-sprayed double layers coating were mainly composed of HAp, Ti, and TiO_2 as minor components. EDS analysis also showed the co-existed of HAp and Ti at the HT intermediate layer. The higher bonding strength of HAp top coating layer was expected to result from the unclear interface of the two coating layers.
View full abstract
-
Yasutomo UETSUJI, Tomoyuki OHNISHI, Kazuyoshi TSUCHIYA, Eiji NAKAMACHI
Article type: Article
Session ID: 2815
Published: September 07, 2007
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
In this study, we challenged to derive new piezoelectric materials with biocompatibility by first principles calculation. Firstly, constituent elements of biocompatible piezoelectric materials have been specified by HSAB method from the viewpoint of interaction energy with in-vivo molecules. Secondly, in order to create a perovskite-type crystal structure with good piezoelectric response, the combination of biocompatible elements was selected to satisfy geometric stable condition defined by tolerance factor. Then, we focused on silicon oxides and investigated on phonon vibration mode at paraelectric phase of cubic structure and piezoelectric response at ferroelectric phase of tetragonal structure.
View full abstract
