Glancing angle deposition (GLAD), in which the deposition angle is highly inclined to the substrate normal during vapor deposition, enables fabrication of thin films comprised of structured nano-elements. In general, when a thin film is released from a substrate, the film spontaneously bends or rolls-up to form an external structure such as tube due to the presence of residual stress. It is however challenging to realize desired three-dimensional external structures by controlling the bending of films. The bending deformation depends on internal 'shape' of films as well as the mechanical properties of materials. In this study, we tried to control the external structure of thin films by controlling the shape of constituent nano-elements by GLAD. We fabricated Ti thin films comprising of oblique nanocolumns, in which the porosity in the column-tilt direction is larger than that of the transverse direction, on a sacrificial resin layer coated on a Si substrate by GLAD with the deposition angle of 60 degrees. When the film was released from the substrate, bending deformation occurred around the transverse direction to form tube structure regardless of the sample shape, suggesting that we can control the direction of bending by using the anisotropic shape of nano-elements.

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The automotive industries expect to replace conventional steel with CFRP to decrease fuel consumption. Adhesively-bonded joints are applied to many CFRP structures, and surface preparation is needed to indicate strong adhesion. However, conventional surface preparations increase process of works. In the present study, we propose in-mold surface preparation, and control the adhesion of the interface. In the in-mold surface preparation, the mold with the micro structures is transferred to the CFRP surface by pressure forming process. We evaluated the adhesion of CFRP/adhesive interface with in-mold preparation under mode II loading, and confirmed the validity of the in-mold preparation.

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Probabilistic safety assessment is an effective method to improve the conservative safety factors on low cycle fatigue life of turbine blades used in jet engines. This paper focuses on uncertainties of low cycle fatigue design life result from small samples and surface finishes. Improvement of uncertainty of design fatigue life, reflected from small sample tests, by use of inspection data is verified through Bayesian update and virtual inspection data. Furthermore, tension-compression low cycle fatigue tests on Inconel 718 were conducted with the specimens, of which surfaces were finished Ra 0.8, Ra 6.3, and Ra 12.5. The results indicates strain-amplitude dependence of the influence of surface finishes on low cycle fatigue life. In order to investigate the effect of surface finishing on low cycle fatigue life, local misorientations of surface layer of specimens are measured by EBSD.

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In plastic forming, deformation resistance of a material is generically decreased by superimposed ultrasonic vibrations (UVs) as "Blaha effect". In order to clarify the mechanism of the stress decreasing, stress-strain/time behaviors were experimented by the compression tests that superimpose the UV with different amplitude voltages to fixed strain and constant deformation rate, and the UV to the ratio of different specimen diameter versus horn tip diameter. Stress decreasing rate was increased with increasing amplitude voltage and was increased with decreasing diameter ratio.

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In this study, thermal fatigue lifetimes of S45C/Cu/Si_3N_4 composites subjected to cyclic thermal loadings were evaluated. First, S45C/Cu/Si_3N_4 composites with interlayer thicknesses of 150 and 200 μm were prepared. Next, thermal fatigue tests were carried out at temperature differences of 275 K and 575 K. The cycles to failure of the composites were evaluated and a model for predicting thermal fatigue life was proposed. In addition, the suitability of theoretical model was considered. The results revealed that temperature difference of cyclic thermal loading and thickness of Cu interlayer have effects on thermal fatigue lifetimes.

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Cu/AlN composites used as electronic devices have a problem with thermal stress. The thermal stress has an effect on residual strength of the composites. Here we report the residual strength of the Cu/AlN composites subjected to cyclic thermal loadings. We perform finite element analysis, cyclic thermal loading tests and residual strength on the Cu/AlN composites. The results reveal that microscopic damage of AlN substrates reduce the residual strength of the Cu/AlN composites.

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To improve tank safety for fuel cell vehicles and promote the application of aluminum alloys to high-compression hydrogen gas tank liners, it is important to clarify the fatigue properties of aluminum alloys as affected by atmospheric hydrogen. In this study, the effect of elastic fatigue deformation on hydrogen diffusion for 7075 aluminum alloy was investigated by means of hydrogen microprint technique. The fatigue test was carried out under the various parameters for frequency (10 Hz, 1 Hz, or 0.1 Hz) and applied maximum stress (80%, 60%, or 40% of proof stress (525 MPa for 7075-T6 alloy)). In all fatigue tests, accumulated hydrogen was mainly observed within second phase inclusion such as Al_7Cu_2Fe. This shows that Al_7Cu_2Fe acts as hydrogen diffusion path during elastic fatigue deformation. The amount of hydrogen accumulation increased with decreasing fatigue test frequency, which shows that the hydrogen diffusion is influenced by deformation time. Hydrogen accumulation also increased with increasing maximum stress, which indicates that hydrogen evolution during elastic fatigue deformation is controlled by stress-induced diffusion.

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In the previous study, we have discovered 21 novel biocompatible lead-free piezoelectric materials in perovskite-type oxide through first-principles calculations. The purpose of this study is the prediction of phase diagram to support the fabrication of the discovered novel materials. The cubic stable structure was estimated and the phonon properties were analyzed. Then, the soft mode was identified with eigenvalue and the asymmetric stable structure caused by the soft mode was evaluated. Total energy and spontaneous polarization of some stable structures were approximated by Gibbs function based on a thermodynamic theory which can be utilized for the prediction of phase diagram. The proposed method was applied to an existing piezoelectric material, BaTiO_3 and energy distribution was presented.

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In recent years, reducing the weight of aircraft is crucial for realization of the low-carbon society. Hence, carbon fibre reinforced plastics (CFRP) with lightweight and high mechanical properties have been widely applied to components of aircraft. One of the applications is a CFRP fan system of a turbo-fan engine. However, foreign object damage (FOD) by such as bird striking is one of the crucial issues in application of CFRP to the fan system. This paper presents experimental and numerical characterization of high-speed impact damage processes in CFRP laminates. First, high-speed impact tests were performed using an impact testing machine with the use of an electric heat gun. The surface and internal damages of the CFRP specimens were observed by using optical microscopy together with radiography. Numerical analysis simulation was carried out to reproduce these damages. Especially cohesive elements were inserted into all the interlayers to express the delamination. The simulation was compared with the experimental results to understand the damage evolution mechanism. The simulations were in good agreement with the experimental result.

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In this study, we tried to fabricate much amount of Fe nanowires from a Fe plate. The surface of the Fe plate was frist oxidized by HNO_3 solution. The plate was then bended and heated at 300, 450 and 600℃ for 3 hours. Much amount of Fe nanowires having the diameter of 40 nm and the length of 1.5 μm were successfuly fabricated. Moreover, we examind the struture of the fabricated Fe nanowires.

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This paper presents experimental characterization of a piercing process of CFRP thin laminates. Recently, application of CFRP is expected to expand to automobiles and mobile electronics. Hence, the present study was carried out to establish a method for a short-time and low-cost piercing process of thin CFRP laminates. A CFRP plate was pierced under various conditions by using a punch drived by a hydraulic testing machine. Surface and internal damages of the CFRP plates were observed by using optical microscopy, stereomicroscope and together with soft X-ray analysis. A damage process was then discussed on the basis of the experimental result. Next, the influence of clearance and shape of a punch on the damage in the specimen was examined to optimize clearance. Especially, the effect of clearance and shape of a punch on delamination in cross-ply laminates was investigated.

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In this paper, damage process caused by shear cutting in CFRP laminates was characterized by experiments and numerical simulations based on the smoothed particle hydrodynamics (SPH). Unidirectional laminates were cut by using a shear cutting jig, and the damage states and cutting forces were characterized with respected to the clearance, which was a distance between upper tool and lower tool. Shear cutting process was then analyzed based on SPH. Two types of model, i.e., homogeneous model and heterogeneous model were employed to represent a unidirectional laminates. In the homogeneous model, various types of damages including fiber failure and transverse cracks were predicted. Based on the heterogeneous model that divided into fibers and resin, fiber failure and matrix failure were predicted, and the damage state and the cut pattern were similar to those of the homogeneous model. By the comparison with experiments and simulations, we evaluated the damage extension process caused by shear cutting in CFRP unidirectional laminates.

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In this study, The relationship of between the load stress and number of cycles (S-N curve) about Carbon Fiber Composite Cable (CFCC) are obtained by fatigue testing of repeated tensile cycles. The strain in 4 edges points of thimbles of both ends, that are assessed with strain gauges. In S-N curve behavior, CFCC is fixed in number of cycles to failure of load amplitude about 65 kN. Breaking point of CFCC is edge of thimble in both ends.

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Multiferroic composite materials consisting of ferroelectric and ferromagnetic bodies enable us to control magnetic flux density by electric field and electric flux density by magnetic field. Because microscopic crystal morphology affects macroscopic material property strongly, it is necessary to design material microstructures by computational simulations. In this study, multiscale analysis method based on homogenization theory was developed to estimate macroscopic material properties with consideration of microstructure. The developed method was applied to polycrystalline multiferroic composite materials. As a computational example, the effect of microstructural volume fraction on homogenized material properties was investigated.

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The embedded strain gauges in a PQC-TEG in a silicon chip were applied to the measurement of the change of the residual stress in a transistor structure with a 50-nm wide gate during thin film processing. The change of the residual stress was successfully monitored through the process such as the deposition and etching of thin films. In addition, the sensors were also applied to measurement of thermal residual stress in a silicon wafer caused by flip-chip bonding and the stress was successfully monitored. The sensitivity of the measurement was 1 MPa and it was validated that the amplitude of the fluctuation exceeded 100 MPa. This technique has applicability to monitoring the residual stress from front-end wafer process to packaging process.

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In order to assure the reliability of advanced gas turbine systems, it is very important to evaluate the damage of high temperature materials such as Ni-base superalloy under creep and fatigue conditions quantitatively. The mechanism of the directional coarsening of γ phases (rafting) of the Ni-base superalloy under uniaxial strain at high temperatures was analyzed by molecular dynamics (MD) analysis. The stress-induced anisotropic diffusion of Al atoms perpendicular to the interface was observed clearly in a Ni(001)/Ni_3Al(001) interface structure. The stress-induced anisotropic diffusion was validated by experiment using the stacked thin film structure with the (001) face-centered cubic interface.

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Microtexture dependence of the strength of electroplated copper bumps used for fine interconnections in electronic packaging were investigated experimentally considering the effects of their electroplating conditions and heat treatment after the electroplating. Not only Young's modulus but also the strength of electroplated copper thin films changed drastically depending on the change of their micro texture, and these values were significantly different from conventional bulk copper.

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This paper deals with the evaluation of crack growth behavior by stress corrosion cracking (SCC) based on non-linear fracture mechanics taking account of plastic deformation. Compact tension test is carried out to evaluate the crack growth behavior by SCC under small-scale and large-scale yielding condition. Four-point bending tests are also carried out to evaluate the crack growth behavior by SCC in plastic deformation field. The crack growth rate is almost same at the same level of the equivalent stress intensity factor defined by J integral, irrespective of yielding condition. The equivalent stress intensity factor is an appropriate parameter for evaluation of crack growth by SCC in plastic deformation field.

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Osteoarthritis (OA) is the most common type of arthritis. It is reported that about 30% of Japanese over 60 years old suffer osteoarthritis of the knee, and a lot of them need knee braces or supporters in daily life. A new type supporter, which is called rotating shaft type supporter, is invented for this disease. In this study, the optimal design of the frame of this type supporter is investigated. The design objective is to create holes in the design domain (i.e. create new sewing lines along the curve of holes) so that the frame can be fixed to the flexible cloth cover strongly and stably. It can also reduce the weight of the supporter, and improve the air permeability. Since it is important to guarantee the enough stiffness in load direction, a topology optimization approach is applied for the optimization analysis.

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In this paper, constant tensile load tests under simulated primary water environment in boiling water reactor are carried out for sensitized stainless steel type 304 to evaluate influence of applied load and loading time on crack initiation and coalescence behavior by SCC. As a result, many stress corrosion cracks initiated is observed on the smooth surface of specimen, and coalescence of neighboring cracks is also observed. The number of cracks and crack length increase with increasing loading time and applied load. The crack length ranges from 0.02mm to 3.0mm. The crack length which is less than 0.1mm is normal-distributed, and the value of mean and variance of normally distribution are about 50μm and 17μm, respectively.

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Nowadays, a biomass-based material, called "green composites" attracts considerable attention, because this material consists of natural fibers and biodegradable or thermoplastic resin. On the other hand, green composites are inferior to strength and stiffness in comparison with GFRP and CFRP, and therefore limited in practical use to only secondary structural members. The purpose of this study is thus to develop a green composite with high strength and stiffness through cyclic load application. In the past, the process of uniaxial cyclic loading was applied for a short ramie/polypropylene (PP) composite. According to the result, the composite mechanical properties were improved through this process, but showed anisotropy. In this study, we tried to apply the process of a biaxial cyclic loading for a short ramie/PP composite to improve the mechanical and anisotropic properties.

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The natural fiber reinforced biodegradable plastics, which can be carbon-neutral materials, are investigated as alternative materials to glass-fiber reinforced plastics. In this study, unidirectional jute spun yarn reinforcement PBS composites were fabricated, and the fatigue tests were conducted to investigate the fatigue property.

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In this study, a new welding method which utilizes conductivity of CFRTP (Carbon fiber reinforced thermoplastic) is proposed. Electrical current is applied through the CFRTP single-lap joints in thickness direction. Since resistance of joining surface is the highest in the current path, the joining surface is preferentially heated by Joule heating. In this study, surface welding was conducted by the proposed method. By applying constant voltage of 10.3V, the joint-surfaces were heated above melting temperature of the material and were welded. In order to evaluate lap-shear strength (LSS) of welded joints, tensile lap-shear strength tests were conducted. As a result, LSS are 22.0MPa (CF Fabric/PEI) and 22.5MPa (CF Fabric/PPS). These strengths were comparable to those that were welded by traditional resistance welding. It is also found that LSS is changed with welding pressure of joint parts. Also, in order to elucidate the mechanism of self-resistance welding, the temperature of specimen and the current during welding process were measured. As a result, it was found that the process of self-resistance welding could be divided in two stages.

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The purpose of this study is to bring out strain effects on outputs of polycrystalline silicon solar cells. Strains on crystalline silicon change the bandgap which relates to the open circuit voltage of solar cells. Strains are added by putting a load on a specimen. Strains are evaluated by the stress analysis using Finite Element Analysis and the measurement using strain gauges. The specimen was designed which can deliver 0.21 % tensile and compressive strain on the solar cells. In order to deliver strains on a base plate to solar cells, A7075-T651 was chosen as the base plate material. The base plate and solar cell modules were bonded by an epoxy adhesive. 1-V characteristics of the specimen were measured by exposing incandescent light to the specimen and the maximum output of the specimen was calculated. The maximum output of the specimen decreases 21 % with 0.126 % tensile strain.

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The maintenance program for building equipments is basically done in time-based concept. The inspection periods are determined for each item which is composed of plural parts; however, this inspection interval is determined on experience-basis and its background is not necessarily clear. In order to rationalize the maintenance program, the application of available data such as failure reports given by customers, and inspection data reported at periodical maintenance is extremely important. Unfortunately, this information is not necessarily utilized sufficiently at this moment. In this research, we try to quantify risk by calculating failure rate of each maintenance item using statistical method and by defining consequence accompanied by failure. Finally, we develop the method of optimizing the maintenance program based on risk.

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In this research, a technique for characterizing thin coating on steel plate and imaging the distribution of coating thickness by utilizing acoustic resonant phenomenon is reported. First, acoustic properties (acoustic impedance, sound velocity and density) of thin coating were measured by the acoustic resonant spectroscopy technique. Using the measured sound velocity of the coating, the thickness distribution of the back side coating of the sample was successfully obtained by scanning the focused-type ultrasonic transducer.

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This paper discusses optimum design of a stiffened composite panel, which is used in aerospace structures. Anisotropic thermal expansion coefficients of the composite laminates causes complicated deformation of the panel after the curing. In previous researches, stacking sequence optimizations were performed without considering thermal deformation: a response surface was used to obtain an objective function, and lamination parameters were sued as variables for the response surface of the objective function such as buckling load. However, the thermal deformation must be considered as a constraint factor for actual composite structures. In the present study, therefore, thermal deformation is dealt with as a constraint for a stacking sequence optimization problem. Three surrogate models of the thermal deformation are discussed here: a conventional method using lamination parameters; a new method using thermal coefficients; a modified new method As a result, the modified new method is shown to be effective for the surrogate model.

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The Electrical Resistance Change Method (ERCM) is useful for inspection of CFRP (Carbon Fiber Reinforced Plastic) structures, because electrical conductivity of carbon fibers in them can be used as a sensor for damage detection. Fatigue damages need to be detected using the ERCM because these damages decrease residual strength and reliability of CFRP structures. This study experimentally deals with cyclic loading tests of CFRP laminates using the ERCM. Moreover, the mechanism of electrical resistance change caused by cyclic loading was investigated. First, the electrical resistance change was measured by four-probe method for CFRP laminates with stacking sequences of [0/±45/90]_s and [0_2/90_2]_s. As a result, the electrical resistance of CFRP laminates with the stacking sequence of [0/±45/90]_s decreased with the cycle number. By contrast, that with the stacking sequence of [0_2/90_2]_s increased with the cycle number. The mechanism of the resistance decrease of quasi-isotropic laminates under cyclic loading, which could have not been explained by the conventional theories, was revealed in this study. The test results indicate that residual strain in ±45° plies caused by cyclic loading increases fiber-fiber contact, which decreases resistance.

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In this study, an accelerated fretting fatigue testing method by using ultrasonic torsional fatigue testing machine was developed. Fretting fatigue tests for S45C specimens by using the method were conducted. To compare with the results, the fatigue tests for smooth specimens were conducted. In the case of fretting fatigue, a crack was initiated from a fretting part. The results showed that fretting fatigue tests can be performed by using an ultrasonic torsional fatigue testing machine.

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In order to investigate the effect of notch-tip geometry on the fracture toughness of fine-grained isotropic graphite ETU-10, three-point-bending fracture toughness tests have been performed by using two types of single-edge notched beam specimens with different notch angles of approximately 15° and 30°. In this test, the load-displacement curve was measured by using the load cell and the laser displacement sensor. The values of the fracture toughness were calculated based on linear elastic fracture mechanics by using the maximum force which could be obtained by the load-displacement curve. As a result, the values of the fracture toughness of the specimens with the notch angles of approximately 15° and 30° were 0.933 MPa m^<1/2> and 0.926 MPa m^<1/2>, respectively. This suggested that the values of the fracture toughness were not affected between the notch angles. Further work has been ongoing to discuss the effect of the notch-tip geometry such as angle and root radius of notch in terms of finite element analysis.

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Fuel cell is expected in realizing a low carbon society. However, objective comparison of cell is difficult because cell has been developed by various manufactures. Therefore, strength evaluation method of cell hasn't been established. In the present study, we aimed at the establishment of strength evaluation method about cell. Same models of small punch testing were made by finite element method. Therefore, in the contact state of the plates, change in stress distribution into experiment condition was analyzed by finite element method. As the results, experiment condition that contact stress is higher is found.

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In general, quenching is a method for giving high mechanical strength, toughness and fatigue resistance to steel. It is widely applied in various machine parts such as spindle, gear and so on. When carbon steel is carried out quenching, it is known well that quenching crack occur in the cooling process. In order to prevent quenching crack, it's necessary to erect numerical analysis technique for calculating thermal stress with a high degree of accuracy in the cooling process. Additionally, it is necessary to bring out genesis phenomenon of quenching crack in perspective of fracture mechanics, and erect the technique to evaluate genesis of quenching crack. However, estimation method using fracture mechanics for quenching crack doesn't have been yet established. In the present study, we measured fracture toughness of quenched medium carbon steel. Thermal stresses during the cooling process are analyzed using finite element method and then put genesis of quenching crack in perspective of fracture mechanics. As a result, it's conceivable that the estimation method used stress intensity factor can evaluate genesis of quenching crack.

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Crack propagation analysis for ceramic bearing orbit under rolling contact was performed using finite element analysis and fracture mechanics. A fracture-mechanical approach was proposed for evaluating stress intensity factor, and its appropriateness was examined by the results of the analysis and the experiment. It was found that the analysis results nearly agreed with the experimental results, which verified the fracture-mechanical approach.

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Effect of grain boundary precipitates on the high speed deformation of Hadfield steel was studied. The Hadfield steels with carbide on the grain boundaries or not were prepared by heat treatment. The tensile tests at various strain rates from 10^<-3>/sec to 10^3/sec were examined at room temperature. At slow strain rate (10^<-3>/sec), the both samples with/without carbide were large work-hardening with serration due to the dynamic strain aging, followed by fracture without local elongation. With the increasing of strain rate, the uniform elongations of both the samples are recovered and, furthermore, the local elongation can be found at strain rate higher than 10^0/sec. At the highest strain rate (10^3/sec), the both samples show large ductility. Observation of the fracture surface at slow strain rate indicate mainly inter granular fracture in the sample without carbide, whereas the grain boundary fracture can be found in the sample with carbides. On the other hand, the fracture surface of the sample show dimple pattern whichever the carbide exists or not. This indicates that the ductility of Hadfield steel at high speed deformation is attribute to something else than brain boundary carbide, such as solute carbon.

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This paper examines the high accuracy of the crack propagation analyses by using the Finite Cover Method(FCM). FCM was employed to simulate the crack propagation in elastic-plastic materials, and enables arbitrary crack generation and propagation. The linear triangular element is using by the conventional finite cover method. A high-order element has high accuracy of the stress, but it includes the instability, so this paper applied P1-isoP2 element to FCM.

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This paper proposes a laser microscopic in-situ observation method for fretting fatigue processes and shows the results of the observation of wear processes and crack initiation processes. In particular, the authors produced a new clamping method in attaching a proving ring which are necessary for the laser microscopic observation because non-uniform contact condition and steps on the interface between the specimen and the contact pads concealed wearing situations in the case of using conventional clamping method. The new method improved contact condition and reduced the height of the steps and the new method led to initiate an inclined crack whose direction was almost perpendicular to the direction of maximum principal stress. The result of observation revealed that the distance of the position of a top of wear powders from the outer edge of contact pad rapidly increased in the early period of a fretting fatigue life and became a saturated state in the 50% of the FF life. The crack initiation occurred in the vicinity of the maximum wearing region before the wear position had saturated.

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Vacuum assisted Resin Transfer Molding (VaRTM) is widely used for molding of composite structures. This paper presents a method to observe resin impregnation in a VaRTM process without embedding sensors into composite structures. The resin flow is estimated by an approach integrating a stochastic simulation of a VaRTM process with values of electrical capacitance measured between pairs of electrodes on a molding tool. This method is based on the ensemble Kalman filter (EnKF), known as a sequential data assimilation technique. The proposed method was examined by a numerical experiment and it was confirmed that the resin flow front could be estimated.

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Since the resin composite is subject to cyclic stress in the oral environment, an understanding of the fatigue strength of resin composite is very important for keeping safety use. In this study, we investigated fatigue strength of resin composite under three-point bending and axial loading. It was found that the axial fatigue strength was lower than the bending fatigue strength.

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Steam is one of the industry infrastructure as the same as water, gas and electricity. Therefore, there is demand for the low-cost and reliable boiler. This is to explain our innovative boiler design which is different from the ordinary structure standard, by using FEM analysis and strain gauge measurement method. And also this is to introduce our effort of pursuing safety.

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Toray commenced the world's first commercial production of PAN-based carbon fiber in 1971 and have provided various fibers, prepregs and the composites for aircraft, automotive, sport, civil and industrial applications. From the late 2000s, many aircraft such as A380 and B787 have been drawn attention due to the extensive implementation of CFRP, however this application can be traced back to the production of the B777 tail wing in the early-90s. Conventional CFRP have advantages such as high strength, lightweight, anti-corrosive properties, however due to the brittle characteristics, the concern of impact loading narrowed its application primarily to secondary structures in the 80s. Toray developed high strength-medium modulus carbon fiber, T800H and toughened interlayer prepreg, which dramatically increased the composite properties of compression after impact (CAI), achieving the adoption to B777. Currently, aircraft structures employ mainly prepeg autoclave molding techniques, however from the perspective of increasing the build-up ratio and reducing the cost, Toray is developing a vacuum resin transfer molding (Va-RTM) method on MRJ tail wing collaborated with MHI. The RTM process is an in-house developed technology commenced in the 90s and is applied to the MRJ project employing Va-RTM and have recently established a joint venture agreement with Daimler for mass produced automotive parts utilizing a high cycle RTM process. This presentation will contain the history of CFRP adaptation in aircraft and automotive applications with the progress of Toray's R&D, and the review of approaches and possibilities for new applications.

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Multidisciplinary design optimization technology which can predict the lightest gauge and material grades combination of body components while maintaining stiffness, crashworthiness and other performance attributes has a potential to pursue optimal design of structure. However it is difficult to maintain calculation accuracy of approximation model of the analysis technology for non-linear phenomena such as collision. In this paper, improvement of data sampling method and approximation model from the view point of material deformation were descrived. And design optimization process for body structure subiected to stiffness. NVH and crashworthiness has been established.

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From past to present, the seismic resistant design have changed whenever the architectural and civil structures sustained serious damage due to unexpected earthquakes. The bridge design has changed greatly for the cause of the Great Hanshin Earthquake and the seismic resistant design of general girder bridges has made great progress. On the other hand, as the middle or large span bridges such as arch bridge and truss bridge have complicated behavior, it is difficult that the design method of girder bridge apply to these type bridges. The authors have developed the hysteresis brace (Damper Brace) as the energy-dissipating device and verified the elasto-plastic characteristics of Damper Brace by quasi-static and dynamic shaking table tests. The development of this Damper Brace enabled the rational design of the arch bridge.

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A state-of-the-art bullet train, class395, was developed for high speed line in UK. Under the development stage, harmonization between Japanese technology and UK request was one of key issues. In the paper, as a representative of the harmonization, approach in crashworthiness area was described. In order to meet the standard of RGS and TSI, crushable structure for absorption of energy during collision, and survival structure for secured space for passengers were prepared. As a result, based on results of simulation and experiment, the carbody was confirmed to meet the both standards.

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Carbon nanotubes (CNTs) have attracted enormous attention from many researchers of material science, and their physical properties have been intensively clarified. The next step of carbon nanotube research should be development of high performance CNT materials with industrial applications. Production of CNT composites represents one of great targets for the application. In this study, alumina has been selected as the matrix of CNT composites because of its low cost and high performance. The final goal is to develop a design-fabrication-evaluation methodology for CNT ceramic matrix composites and to produce high performance composites on the basis of the method to be developed. MWCNT/alumina composites were prepared by a simple mechanical mixing method followed by pressureless sintering. The effects of MWCNT addition on mechanical, tribological and electromagnetic-wave absorption properties of the pressureless sintered-MWCNT/alumina composites will be discussed.

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We have introduced the Mori-Tanaka theory as a new micromechanical model to predict the Young's modulus for carbon fibres, that takes into account both the crystallites and amorphous components of the carbon fibre structure. The axial elastic constants of the bulk carbon fibres were measured directly by X-ray diffraction (XRD) and an axial shear modulus of about 20 GPa was calculated. The elastic constants of the amorphous carbon in the fibres and the volume fractions of crystallites were estimated using micromechanical models. It was found that the amorphous modulus was approximately 200 GPa and the volume fractions of crystallites were 0.4 to 0.8, depending upon the nanostructure of the carbon fibres. Also, as it is known that the Raman G band shift rate per unit strain is related to the crystallite modulus, the data indicated a nearly constant value of 1.1 TPa, consistent with direct measurements upon graphene. The results show clearly that the behavior of carbon fibres can be expressed through a composite mechanical model that assumes they consist of both crystalline and amorphous carbon components.

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