In this study, we have suggested the new joint configuration, which has a curved surface at a bonded part, and we have named it an "adhesively waved butt joint". Mechanical properties in some present joints subjected to static tensile load were analyzed, using finite element method. FEM analyses to clarify the stress field at the bonded part were carried out. We have investigated specially in focus joint named "double-waved butt one". To confirm the reliability of the analytical results, experiments about strain distribution by using strain gauges were performed. As a result, it was found that stress concentrations occur at both edges of adhesive interfaces. Furthermore, the value of maximum stress decreased as wave number at bonded part increased. It was proved that the strain distribution by analytical result is consistent with that measured with strain gauges.

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Recently, the devices have been progress miniaturization and ultra thin in kinds of fields, especially microelectronic devices and information storage media. Therefore, the measurement of near-surface is very difficult. However, their characteristics are very important in engineering. In this study, influence of phase transformation on mechanical properties of single crystal silicon is investigated. This paper describes how to write a manuscript.

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It can be considered that much energy is necessary to recover large strain by shape memory effect and superelasticity. Martensitic transformation is important factor of these effects, and possible process for storing energy. In this study, potential energy change of the atoms near the habit plane has been calculated for martensitic transformation in Ti-Ni equiatomic alloy by Modified Analytic Embedded Atom Method (MAEAM). Phase transformation is modelled by crystallography of martensitic transformation by Wechsler, Lieberman and Read (WLR theory). Furthermore, potential energy change has been calculated for slip deformation in B2 structure to compare with result for martensitic transformation. These results showed that B19' martensite phase was unstable than B2 austenite, but this transformation is the easiest process than other deformation systems. This means that martensitic transformation and stress induced transformation in Ti-Ni alloy are reversible deformation without plastic deformation.

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To improve the plastic formability of AZ31Mg alloys, this study examined the relation between mechanical properties such as plastic workability and changes of structural refinement after the multi-axial alternative warm forging (MAF) and roll working with recrystallization heat treatment or high-temperature heat treatment. In MAF, work pieces were rotated through 90° on the longitudinal axis between each forging press. This procedure was successful to be introduced large strain into materials. Rolling condition was total redaction 50%, temperature 493K, and water quench. The plastic formability assessment was carried out by conical cup test at testing speed 10mm/min under temperature (293-523K). It was found that at test temperature 423K, AZ31Mg formability was more than those of A5083 at all process. Especially, AZ31Mg alloys with high-temperature heat treatment had good conical cup values at room temperature to close to those of A5083.

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Because the charge transport property of graphene is superior to that of silicon, graphene is expected to be a good material of the next generation for electronic devices, and attracts much attention of researchers. Single-layered graphene is a zero band gap semiconductor. Accordingly, techniques of adjusting its band gap are necessary to its application. One of such techniques will be the use of bilayer graphene. In this article, the stable structure of bilayer graphene is obtained by means of molecular dynamics. And the band structures of the local parts of the stable structure are calculated by means of first-principles calculation. It turns out that the magnitude of the band gap is changed by shifting the relative configuration of the two layers of bilayer graphene.

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We are studying about construction of system of making to visible of internal defect. As the former stage, we developed the device that was able to exchange various ultrasonic probe and to measure high sampling frequency. As the checking operation of the device, we measured the wave reflected at the top of the sample and the bottom of the water tank. As the result, we confirmed precision of the device because the result of the calculation was corresponding to the height of the sample. However, because the influence of the white noise with the amplifier was large, the signal processing was necessary.

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Recently, adhesive bonding has been used in functional composite structures. The purpose of our work was to clarify the characteristics of strength for metal-CFRP adhesive bonded structures. We analyzed four types of single-lap adhesive joints subjected to 3-point bending moment by finite element method. In addition, to validity of FEM analysis, strain distribution experiment using strain gauges were performed. By comparing the results of four different types of joints, we obtained conclusions as follow. Under all joint combinations, each stress component and Maximum principal stress distribution at adhesive layer were singular behavior, and indicated Maximum stress value at edge in longitudinal direction. Maximum stress value at adhesive layer using SS400 as material of one side adherend proved to be the lowest in the four kinds of joint combination.

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Recently, porous aluminum with very lightweight and high energy absorptivity has attracted special interest as a new functional material. These properties are governed by the pore structure in porous aluminum. However, there is little research on the change of pore in the compression process of porous aluminum. In this study, the compression test of porous aluminum is carried out under X-ray CT observation and the deformation process of individual pore in porous aluminum was examined under compression.

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Porous aluminum is a lightweight material with high energy absorptivity. In this study, porous aluminum/dense steel sandwich panel was fabricated by friction stir processing (FSP) route. In the FSP route, mixing a blowing agent into aluminum and bonding the aluminum precursor to dense steel plate can be conducted simultaneously. In the manufactured porous aluminum/dense steel sandwich panel, diffusion bonding was realized and Fe-Al intermetallic compound was formed at the interface of porous aluminum and dense steel. Moreover, the sandwich panel was fractured at a porous aluminum part.

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Porous aluminum is expected to be applied as a multifunctional material in automobiles because of very lightweight, high specific strength and high energy absorptivity. When aluminum alloy die castings are used as a starting material in the fabrication of porous aluminum, the gases intrinsically contained in the die casting can be used to generate pores. From the fact, it can be expected that porous aluminum with high porosity can be fabricated by adding a small amount of blowing agent. In this study, the amount of blowing agent from 0 to 1.4 mass% is added to ADC12 aluminum alloy die castings containing three different amounts of gases and porous aluminum is fabricated by the FSP (friction stir processing) route precursor method. The variations of porosity and pore structure with the amount of added blowing agent are investigated. Through the experimental results, it is shown that, by using a blowing agent of approximately 0.6 mass%, ADC12 porous aluminum can be fabricated with high porosity and good pore structure.

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Titanium alloys formed by a Selective Laser Sintering (SLS) method include many defects. In order to improve the fatigue and corrosion properties of the SLS samples, Fine Particle Peening (FPP) was introduced. When treated with high speed steel particles, almost all defects disappeared within 30 seconds of treatment. However, no noticeable effect was observed on fatigue strength and corrosion resistance of the specimen.

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The focus of this study is to clarify effects of interface wedge condition in Metal side on the bonding strength of ceramic to metal joint. Geometrical interface shape at the edge of the interface is characterized by wedge angle in both sides of the ceramic and metal defined as a configuration angle between free surface of each material and the interface. As the wedge angle of Si_3N_4 is right angle, the wedge angle of Ni is set over 30°≤φ_2≤180°. Experimental Results showed that maximum tensile bonding strength was observed at the wedge angles of φ_2=75°. It seems that this geometrical condition is critical conditions of the bonding strength and fracture pattern. Setting φ_2 near 75° improves the bonding strength since it decreases the residual stress near edge of the interface on ceramic side. This paper provides a useful geometrical interface shape to improve tensile bonding strength of ceramic to metal joint.

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This paper provides effects of specimen's thickness on fracture toughness (critical stress intensity factor, K_<IC>) on the major planes of single crystal silicon using controlled surface flaw (CSF) method at room temperature. In this study, effects of geometrical shape of precrack on fracture stress and fracture toughness each specimen thickness. The average of K_<IC> obtained by CSF method was found to be 0.708±0.129 MPa・m^<0.5>, independent of specimen's thickness. The results on fracture stress and fracture toughness contribute to design for micro structures.

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An ionic polymer-metal composite (IPMC) consisting of a thin perfuorinated ionomer membrane, electrodes plated on both faces, undergoes large bending motion when a small electric field is applied across its thickness in a hydrated state. The characteristics of IPMC are ease of miniaturization, low density, and mechanical flexibility. Therefore, it is considered to have a wide range of applications from MEMS sensor to artificial muscle. The deformation characteristics of IPMC actuator depend mainly on driving environment. Therefore, it is necessary to develop the model of IPMC actuator that considers the environmental condition. In this paper, we focus on the effect of solution temperature and ion species that affect the deformation response of IPMC actuator. Based on the finite element analysis, the deformation behavior of IPMC actuator was simulated and compared with the experimental results.

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We developed the water driven stage that uses the water hydrostatic bearings as well as the water piston-cylinder mechanism for driving the table. An important application of the stage is the precision machining of the various precise components, especially small parts in size, such as optical mirrors and lenses. Speed of linear motion of the stage can be controlled by the water flow rate supplied to the piston-cylinder. Therefore, it is needed to control the flow rate in order to maintain the desired feed motion of the stage during cutting operation. The present paper describes a design of the feedback control system of the water driven stage. Mathematical model of the stage and flow control valve are derived. Conventional feedback controller is then designed based on the derived mathematical model. As a result, the feedback control system of the second-order system is introduced. Feedback gains are determined so that desired response can be obtained. Performance of the designed control system is studied via step response.

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A new search space smoothing method is developed for the study aiming at a function-based understanding of the local search approach for heuristic optimization. The algorithm is designed by using the Metropolis algorithm as a local search procedure and is arranged to solve the traveling salesman problem. The schedule for the smoothing parameter and the value of the temperature for the search with the Metropolis algorithm are determined by considering the smoothing-parameter dependence of the specific heat and the temperature dependence of the optimization performance. The resulting algorithm successfully improves the performance of the existing algorithm in combination with the 2-opt local search procedure.

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The impact-wrenching is known as one of the most practical methods for the tightening of bolted joints, but few studies had been made on the process of increasing of clamping force by the successive impacts. This study is made on the clamping force of bolts wrenched by the rotary hammer which gives successive impacts to tighten the bolted joints. The clamping force given by successive n impacts is proportional to √<n>・F_1, where F_1 is the initial clamping force. The process of the tightening of bolted joints is analysis and the theoretical results are compared with the experimental data. The experimental results agree with the theoretical values.

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Hydrostatic bearings are generally used for the spindle and the guide-way of the ultra-precision machine tools. The restrictors of the hydrostatic bearings are the key component determining its performance, such as the load capacity as well as stiffness. The restrictors can be divided into the orifice, capillary and short pipe. The present paper describes a design of the restrictor of the hydrostatic bearing so that the stiffness of the bearing can be maximized. In this paper, a typical thrust bearing structure is chosen as an example for consideration. In particular, an influence of the model of the restrictor on the bearing stiffness is considered. Then, the design results for each restrictor are compared.

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A blood sampling is frequently performed for clinical test, and the skill of needle puncture is achieved by two ways: a simulation practice by using a human body model and experience of clinical trials. However the simulation practice is not considered difference of the kinesthetic sense in venipuncture between the subjects. In addition, in the clinical trials, the trainee cannot practice positively and the poor skill gives the subjects pain. In this study, a needle puncture simulator reproducing the kinesthetic senses of venipuncture using haptic technology is being prototyped. A haptic device of human interface was developed and the force sensor was calibrated. As the results, a motion of venipuncture could be reproduced and it was suggested that a driving torque enhancement on a link mechanism and noise suppression of the force sensor were required.

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Electrode is installed in each of the sciatic nerve (Biceps femoris nerve, Common peroneal nerve, and Tibial nerve) divided into three so that the action potential that generated when rats move the hind limb is measured. When parameters of the measured action potential (Activity time, Max potential,Min potential, and Potential difference) were compared, the parameters of the action potential measured from three nerves were same range. The frequency distributions that result of analysing the action potential by FFT are similar in the three nerves. It is thought that the action potential of similar parameters is used to control the operation of the joint regardless of which joint it is.

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Along with the steadily rising elderly population in Japan, the number of aged persons with difficulties in walking is increasing. We have developed a walking training machine for assisting the gait exercises of the patients in hospitals. The walking training machine has devices to unload patient's body weight and to prevent patient's falling. These devices consist of only mechanical components without actuators, controllers and batteries. A brake mechanism is used in the device to prevent patient's falling. In this paper, first, we analyze the brake mechanism. Second, on the basis of the analysis results, we design and develop a new device to prevent patient's falling. The usefulness of the device to prevent patient's falling is experimentally examined.

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We have developed a small fuel cell vehicle with 1kW fuel cell. The designs of the lightweight steering and the braking system are presented in this paper. The structure analysis were conducted, and the analysis results showed enough safety factors.

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We have developed a single person operated small electric vehicle with 1kW fuel cell (micro FCV). The running tests of the developed micro FCV have been conducted. The experimental results showed that the maximum speed was 22km/h with approximately 800W. The system improvements to achieve the higher speed will be addressed in future research.

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The simple multi-period repetitive control system proposed by Yamada and Takenaga is a type of servomechanism for the periodic reference input. Simple multi-period repetitive control systems make transfer functions from the periodic reference input to the output and from the disturbance to the output have finite numbers of poles. Recently, the parameterization of all robust stabilizing simple multi-period repetitive controllers for the plant with uncertainty was clarified by Yamada et al. However, using their method, it is complex to specify the low-pass filters of which the role is to specify the input-output characteristic. The purpose of this paper is to propose the parameterization of all robust stabilizing simple multi-period repetitive controllers with the specified input-output characteristic.

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We have developed a single person operated small electric vehicle with 1kW fuel cell (micro FCV). The characteristics of the fuel cell used in our system had been investigated focusing on the cooling system. The experimental results showed that the electricity generation characteristics of the fuel cell depended on the ambience temperature. The low power blower control system will be addressed in future research.

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We have developed a small fuel cell vehicle with 1kW fuel cell. The electrical control system and the measurement and control system are presented in this paper. The measurement and control system includes the functions of a thermometer, a hygrometer, a speed meter, a purge controller and a voltage and current sensor. The experiments to determine the accuracy of the measurement and control system were carried out.

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An electrical power generating device using piezoelectric element (PZT) has been developed to convert structural vibration energy into electrical energy. This paper describes the electrical generation characteristics of PZT and PZT including several kinds of additives under vibration load. Vibration tests are performed by using an experimental equipment composed of PZT, weights and a support frame structure. Sinusoidal wave excitation tests are carried out under the condition of the constant initial compressive load acting on PZT. Effects of several kinds of additives, vibration frequency and vibration load on generated voltage and electric power of PZT are evaluated from the vibration test results.

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Since giant magnetostriction was first found at a room temperature in early 1980s, there have been many applications proposed. This paper introduces a novel application which is able to generate electric power by utilizing a reverse transduction of the material called Villari effect. The generator uses vibration as a power source which is easily accessible in our daily life such as traffic-induced ground vibration or bridge vibration. We designed and fabricated a prototype of the generator. This report presents basic characteristics of the prototype and shows potential in practical use.

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We have developed a single person operated ultra small fuel cell vehicle with 20W class fuel cell. A light body was designed by the structure analysis. An efficient gear box and a control circuits by PIC micro computer were also designed. The running experiments showed that the developed vehicle was able to run using the 20W class fuel cell.

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The Mechatronics education curriculum in university teachers course are proposed, and the results of the lecture carried out in university teachers course are discussed. The study materials include PIC micro computer, C language, LED lighting control circuit, and DC motor control circuit. The quetionnaire results showed that the participated students interested in the proposed curriculum very much. However, the students need long time to fabricate the circuit. How to shorten the fabrication time will be addressed in future research.

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Shooting sound of iron golf club is very important to evaluate the added value from consumer point of view. First the pleasant sound is investigated for various clubs. Then FE model based on accurate model of iron club head with shaft is created not only on vibration but also sound radiation. Sound design can be discussed by good use of the model.

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This paper discuses the way to reduce the noise and vibration of thin plate structures. This paper focuses on the musical saw, a kind of musical instrument. The musical saw is thin plate and for playing the instrument, it is need to bend the saw as S-curve. Also thin curved plates are used for various mechanical structures to enhance the stiffness. In case that the curved plates have same dynamic characteristics as musical saw, the plates became noise source. Through the experiment and numerical investigation for the relationship between the mode shape and radiation sound, it is shown the dynamic characteristic of thin plate which contributes the radiation sound.

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This paper describes the application of Response Surface Method (RMS) to the optimization of gear design problems, especially for gear-oriented noise reduction of motorcycles. The requirement of uncomfortable noise reduction is stronger these years because of the improvement of ride feeling as well as environmental preservation. But the gear-oriented noise has strong relation to various design parameters, and it is difficult to specify the parameters to control the noise. RMS is known as an optimization technique, and one of the special features of RSM may be the ability to identify the parameters effective for the evaluation function to be optimized with indistinct experimental or simulation data. The response surface may be derived from several experimental data and/or simulation results. In the present paper, an experimental model of gear system in motorcycle was constructed and gear-oriented noise was measured under various conditions of the center distance, the runout of pitch circle, and the pressure angle deviation. The response surface was proposed from these experimental data, and optimized parameter on center distance and pressure angle deviation were evaluated.

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In this paper, a diagnostics of loosening bolts location in a mechanical structure is examined by observing variation of dynamic characteristics in the high-frequency region of tens of kilohertz. The fault condition is defined as bolt loosening caused by the reduction of tightening torque. Since the variation of the local mode frequency of a bolt head depends on the size of tightening torque, the condition is detected by finding out the local modes of bolt head by using experimental modal analysis. The feasibility of this method is verified by detecting and identifying the loosening bolts installed on an aluminum block that has several natural modes in the high-frequency region.

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This paper describes a bolt loosening detection by a spatial filtering in low frequency region of a few of kilohertz. The spatial filter can be realized using a number of sensors attached to a structure that is less than the number of target modes. The authors have been verified a feasibility of a monitoring methodology for monitoring health and detecting structural damage using spatial filtering. In this study, the loosening of the bolt tightening torques is defined as structural damage of the system. The spatial filter is detected the damage by evaluation of filtered responses in vibration testing of fixed end plate structure.

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In recent years, public concern about environmental affair is growing at the same time, wind power generation systems have been common, it is required to improve the efficiency of wind turbine blades, leading to its operational stability and high efficiency. In this study, it is examined if the blade surface roughness affects the flow condition around the wind turbine blades to control the blade performance. Specifically, the flow velocity around blades are measured by using the hot-wire anemometer, so as to identify the flow behavior on the blade surface and behind the blades. As a result, flow separation is decreased because of contain roughness on the blade, and it is clarified that flow behavior on the blade surface and behind the blades is changed due to the blade surface roughness.

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Experimental study is conducted for the perpendicular axis type windmill. In our study, flap with variable angle is attached to the wings. In our previous study, only flap angles are changed. However, wing attack angles as well as flap angle are changed at this time. And, effect of flap angles and wing attack angles on power generation, efficiency, etc are measured. It is found that using of high wing attack angle is very effective to obtain high generation power. Other findings are that flap angle should be small for low wing attack angle, on the other hand flap angle should be large for high wing attack angle.

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The cross-flow wind turbine is because suited for using the areas where the wind direction changes frequently because it's structure is independent of the wind direction. In order to improve it's performance, it is indispensable to analyze the air flow from the entrance to the exit of the wind turbine. However, in most casses only the outside of the wind turbine has been analyzed in the past research. In this research, the experiment were conducted for the purpose of visualization of the flow inside the wind turbine.The experiments were conducted at tip speed ratios of 0.2, 0.4, and 0.6, and the difference between the visualization results. Results show that the size of the vortex, which abstracted the internal flow of the wind turbine, was the smallest at a tip speed ratio of 0.4, where the maximum efficiency of 0.1 was attained.

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The relationship between pump performance and vibration generated by cavitation was investigated using an axial-flow impeller. By experiments on cavitation of an axial-flow pump, the growth of cavitation due to the change of the Net Positive Suction Head (NPSH) and the pump performance were clarified. Moreover, the frequencies of cavitaion were disclosed by conducting the wavelet analysis on pressure fluctuation and vibration fluctuation at the casing wall. It was made clear in this paper that the tip clearance cavitation is proven to have a specific frequency.

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The pressure inside an oscillating rectangular container filled with water was experimentally investigated by using pressure transducers located at several points on the inner surface of the container. The oscillation is sinusoidal and applied in the horizontal direction. A Fourier analysis of the measured pressure signals was conducted. The excitation frequency is slowly varied near the sloshing resonant frequency of the container, as a result the sloshing state can be considered as steady. Detailed frequency response spectra and a general idea of the spatial distribution were obtained for the amplitude of the three firsts harmonic terms of the pressure. The non-linear effect resulting in a deviation of the sloshing resonant frequency was also investigated.

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This study characterized natural composites as bamboo tips reinforced naturally derived vinyl ester molded with vacuum-assisted resin trandfer molding (VaRTM). The VaRTM process is a variation of vacuum-infusion RTM where one of the solid tool faces is replaced by a flexible polymeric film. The VARTM process is a very clean and economical manufacturing method and suitable for the production of the large-size structure. Only bamboo culms and mixture of culms and leaves were crushed into bamboo tips, finely and roughly, which result in the four types of reinforcements. Bending, vibration and heat transfer characteristics were measured and the possibility of the application to wall material was examined.

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It is known that fatigue life of CFRP composite vessels are seriously reduced by out-of-plane loading. For the improvement of the fatigue life autofrettage treatment is conducted on composite vessels. The objective of this study is to evaluate effects of autofrettage on durability subjected to impact loading. Composite vessels used in this study were made of carbon/epoxy and aluminium liner. Impact tests and damage observation were performed on the composite vessels with and without autofrettage. Tensile fatigue test were also conducted on the specimen simulated as a composite vessels after impact tests, to investigate damage behavior and fatigue life. As a result, absorbed energy of composite vessels with autofrettage became smaller than composite vessels without autofrettage. In composite vessels with autofrettage, delamination was suppressed, and fatigue life became longer. It was clarified that CFRP composite vessels with autofrettage were superior in the impact resistance.

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The polyacrylonitrile (PAN)-based and pitch-based carbon (micron level) fiber-reinforced nanoparticle (nano level) filled polyimide based hierarchical composites have been fabricated using a vacuum assisted resin transfer molding (VaRTM) and autoclave curing. The carbon fibers used in this study were high tensile strength PAN-based(T1000GB) and high modulus pitch-based (K13D) carbon fibers. Fiber orientations of the hierarchical composites were set to [0_<(T1000GB)>/0_(K13D)>]_<2S>. The fiber volume fraction was 50 vol%. Polyimide used in this study was a commercially available polyimide precursor solution (Skybond 703). three different types of nanoparticle (25nm-C, 20-30nm-β-SiC and 130nm-β-SiC) and particle volume fraction was 5.0 vol% used for the inclusion. The tensile properties of the hybrid composites have been investigated. For 25nm-C and 20-30inn-β-SiC nanoparticle filled hierarchical and unfilled hybrid composites, the tensile stress-strain curves show a complicated shape without instantaneous failure.

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The structures of the one-dimenstional alignment of silica nanoparticles and the mechanical properties of their colloidal solutions were investigated. The morphology of the colloidal silica was found to be similar to a "pearl-necklace" structure, which could be formed by adding about 80 wt% of ethanol. The silica nanoparticle solution in one-dimensional alignment showed a weak gel-like behavior whereas the solution with the particles in the dispersion state, which was discretely controlled at lower ethanol concentration, showed a sol-like behavior. The increase in the elastic modulus associated with the change in the particle-dispersion state was highly due to the formation of the worm-like structure connected through Si-O bonding between particles. The attraction force between particles was presumably induced by adding ethanol, reducing the surface charge of the particles.

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The styrene-isoprene-styrene (SIS) triblock copolymer was electrospun from a mixed solvent of tetrahydrofuran (THF) and N, N-dimethylformamide (DMF). To increase the electrical conductivity of the solvent, a small amount of Tetrabutylammoniumbromide (TBAB) was mixed, and microfibers with the average diameter ranging from 200nm to 1μm were obtained. The structural analysis was performed by small-angle X-ray scattering. It was found that, due to the confinement effect and the strong elongational deformation, the microdomain structures in the microfibers differed from the structures observed in the bulk SIS copolymer. Accordingly, the mechanical property of the microfiber specimens was different from that of bulk specimens, which could be attributed to the molecular orientation of SIS in the electrospun fibers.

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In the Waterworks Bureau, the activated carbon was used for filtering the water. After use the activated carbon, they were disposed. In this work, we tried to make that composite to recycle these carbons. These wasted activated carbons were used for the filler of composite materials, and we got the composite with the carbon contents of 10%〜60%. To evaluate of mechanical behavior of these composites, tensile test and stress relaxation test were carried out. The results show the powder contents dependency on tensile strength and Young's modulus. As seen in the results of stress relaxation test, the effect of powder contents on stress relaxation was revealed. To evaluate the electric property, the electric resistance was measured by 4-terminal method during tensile test and stress relaxation test. By the measurement of electric resistance, these composites can be used as smart materials.

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