Mechanical properties are strongly dependent on the microstructures influenced by heat treatment and cold work. Indentation technique was applied to evaluate the mechanical property of the Ni based alloy with various microstructures subjected to heat treatment and cold work. Tensile tests were carried out to understand the effect of the treatments on the mechanical properties. The specimens for indentation test were cut in the tensile axial and radial directions from the rod specimens used in tensile test. The inverse analysis with Kalman filter were carried out on the indentation load-depth curves to estimate the constitutive equation.

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This paper describes the evaluation method of mechanical property in micro-zone, using the indentation technique combined with inverse analysis. The depth sensing indentation technique was applied to evaluate the change of mechanical properties due to the liquid metal immersion, associated with embrittlement, so called LME (liquid metal embrittlement). The effect of imposed stress on the LME was taken by the residual stress development around the material degradation on the interface in contact with the liquid metal. This technique is useful to evaluate the material degradation of a surface of material such as coatings, corroded layer and irradiated layer.

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Effect of hardening treatment on the impact erosion of liquid/solid metals interface was investigated by using modified SHPB (Split Hopkinson Pressure Bar) technique. The hardening treatments were carried out by PVD-implantation coating and Kolsterising surface improving method. The impact erosion strength exhibits good correlation with the hardness measured under a certain indentation load that is related to the magnitude of impact. As a result, the hardening treatment is expectable to reduce the damage due to impact erosion.

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Structural optimization of air flow sensors (AFS) for automotive engine control systems is performed by using CAD and CAE tools. An AFS structure with high measurement accuracy and reliability is obtained based on the integrated results of various simulations conducted by using 3-dimensional CAD data.

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An interatomic potential applicable to strength analysis taking the effects of phase transformation into account is investigated. Temperature and heat of transformation, elastic constants, lattice constants, and binding energy of α and β phase of tin (Sn) are calculated by using a Tersoff-type interatomic potential function. It is found that the calculated values coincide well with the experimental values when the proper potential parameter values are used.

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In the development and design of the product, the facility of processing and assembly process etc. and the thought of the production design that considered the cost becomes an important factor. Therefore, the numerous case studies for the processing nature and the optimization of every part adjustment are required and the optimal design becomes effective means. Thereupon, the wide used optimization program iSIGHT (Engineous Software), wide used structure analysis soft ware FEX (Hitachi, Ltd. mechanical engineering research laboratory), wide used pre and postprocessor CADAS/PRE POST (Hitachi, Ltd.) and also related software (new development) are coordinated each other. (1) In consideration of the cost, the optimization system by shell model was constructed. (2) it applies to the optimization problem of pump frame, and nearly 20 percent of the cost and nearly 28 percent of the weight were reduced, and obtained the expectation to the product application.

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Divertor plates of nuclear fusion experimental reactor are considered to be joined together the plasma facing armor materials having the heat resistance in the heat sink materials of metals cooled activiely. In this study, the divertor model was produced by joining together C/C composite in the oxygen free copper using a titanium foil. And electron beam heating teats were carried out for the divertor model. The temperature charcteristics in the case of heat load test to the divertor model were obtain analytically, and it were compared and was examined with the heat load experiment. The wear was observed in the heat load test in thermal load over about 12.5MW/m^2 on the surface of C/C compsite. When thickness of the titanium foil was 0.05mm, the temperature of each part of the divertor model got analytically showed the value which was smaller than the value got by the heat load experiment.

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This paper describes a study on an inverse analysis method to identify the crack parameters (crack position and crack depth) of a plate using the genetic algorithm (GA). The identification method is based on the eigenvalue change of the cracked plate. The eigenvalues of the plate are calculated by FEM based on Bogner element and are tabulated in advance. Using these tabulated data, spline surfaces are formed and the eigenvalues under arbitrary crack parameters are approximately evaluated on the surfaces. As a result, we can dispense with a large amount of FEM calculation that is necessary to evaluate the fitness function. By maximizing the fitness function in GA, we can predict the crack parameters. To demonstrate the effectiveness of the proposed method, the several identified results are presented.

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A theoretical evaluation method for Pasternak foundation coefficient is presented using the twodimensional elasticity theory. A beam on the Pasternak elastic foundation is modeled as a contact problem of two materials with different elastic modulus. The Pasternak foundation model corresponds to perfect bounding of the interface of the two materials. Using the Airy's stress functions the stresses and displacements of the two materials are determined analytically. The Pasternak foundation coefficient is evaluated from these analytical results.

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In the Fitness for service (FFS) code, the evaluation procedure of the allowable depth for an embedded flaw from that of a surface flaw which has been decided from nondestructive testing is necessary. In this paper, the re-characterization procedure of an embedded flaw was derived by equating the stress intensity factor of an embedded flaw with that of a surface flaw. In addition, the condition that an embedded flaw is considered to be a surface flaw because of ligament plastic breakthrough was clarified. This proposed condition was compared with that of JSME and ASME code.

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The propagation behavior of the crack-like defects due to time dependent fracture mechanics like fatigue was numerically simulated. Fatigue life of multiple cracks using the computer simulation procedure was compared with the experiment results. It was clarified that the error of the Runge-Kutta method was smaller than that of the step method and that multiple cracks coalesce condition as per the API code was certainly pertinent.

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Previously reported topology-based simple cellular solid models and their Boolean operations are theoretically defined. These solid models are defined by giving constraint conditions to cell complex chains having inner cells (mathematical models of objects on databases) in Euclidean space. Their Boolean operations are defined by threetuples of common subdivision operation, set operations, and cellular mapping, basic operations of cell complex chains. These solid models and their Boolean operations are applied to a three-dimensional modeler. In this modeler, Boolean operations of two solid models which have boundary elements (vertexes, deges and faces) in contact can be carried out. Deference between cellular decomposition models, boundary models and simple cellular models is discussed.

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Production of the guitar depends on the experience of the skilled guitarmaker. The guitarmaker also evaluates the sound quality of the guitar by the method called as the tapping. The method depends on the experience of the guitarmaker, too. Therefore, it is desired that the technological production method is developed. The paper presents what kinds of information is physically obtained by tapping. The results are as follows. (1) Analysing sharp sound there is a dominant peak at a frequency. (2) There is a correlation between sound quality and vibration characteristics (i.e.) natural mode and frequency are correlated.

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With this method, we can predict a vibration of a thermally bent rotor quantitatively. In this method, we simply use a couple of bending momentum as an excitation force produced by thermal bending. The amplitude of the bending momentum can be calculated as a bending momentum which causes the thermal bending shape as an elastic deformation. We compared the calculated vibration with the measured vibration of a heater-mounted rotor. The behavior of the calculated vibration agrees well with the behavior of the measured one. The calculation error of the vibration amplitude in resonance is about 12% at the loop of the vibration mode on a critical speed.

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A calculation method of natural frequencies of cylinder is discussed in this paper. A new method to calculate the natural frequencies of a rectangular plate was modified and used to calculation of the natural frequencies of the cylinder. We can calculate the natural frequencies of cylinder for a function of diameter, length, thickness, Young's modulus and density. A factor used in this method shows on a reference. The boundary conditions of both side edges are two conditions of the supported one and the fixed one. The factors are calculated by numerical calculation and compared with the values in a reference. It is found that the calculated values of the factors are near the reference ones. Therefore, the natural frequencies of cylinder become to can easily calculate for the dimensions.

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There are some problems of vibration in mechanical field and anti-vibration is needed for good quality. In general, Laminated composite beam is often used for damping because it is cheap and easy to utilize. In this paper, it is considered that improvement in damping characteristic of Laminated Composite Beam which core layers are separated. Optimal condition for damping, for example Young's modulus and covered ratio are evaluated by numerical analysis.

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This paper describes the instability of a dual rotor system which is caused by internal damping. Transfer Matrix Method is used analytically. The onset of the instability is determined by calculating complex eigenvalue. Internal damping is occurred by viscous characteristic of the shaft material and friction between the disk and the shaft. In single rotor system, internal damping affects the stability in the flexible mode, and instability is occurred beyond the critical speed. In the rigid mode, it does not affect the stability. But, in dual rotor system, it is found that internal damping affects the stability in all modes, and decreases stable area.

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The calculation model of two types of solid structure and divided structure were prepared, vibration characteristics for the models were calculated by a computer program. In the vibration analysis, FEM was used. On the basis of the numerical simulations, the vibration characteristics were compared. The followings were clarified. (1) As the order of vibration mode becomes higher, the vibration amplitude of the divided structure is lower than that of the solid structure. (2) The displacement and velocity of a frame are decreased by the small spring constant between frame and teeth.

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In this paper, we propose the exact derivation method of all anti-symmetric periodic solutions for zero stiffness impact oscillator system, and clarified its mathematical structure. First, deriving process and functional structure of stationary solution for linear system are reconsidered, and extend to anti-symmetric periodic solution for zero stiffness impact oscillator. Second, we gave global representations of anti-symmetric periodic solution for zero stiffness damped and undamped case. Besides, this representation perfectly prescribes all mathematical forms of the anti-symmetric periodic solutions.

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A target of this study is the prediction of noise and vibration on engine structures using analytical statistical energy analysis. We have proposed some techniques for SEA model construction in some design stages. The previous paper described the applicability of the experimental SEA to the prediction of engine vibration. In this paper, we try to make a PreSEA model of an engine structure. In PreSEA, the modal counts of subsystems are required to estimate the cupling loss factors between subsystems.

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The object of our study is the development of a new way to overcome the vibration problem on plate structures by change of structure on structural energy transmission. We recognized the change of structural intensity on plates by the stiffness. The cause of the change has not been able to be explained clearly. This paper discusses the reason that the structural intensity changes using the spring-mass-damper systems. As a result, it is shown that the product of the modal vector and the force on the mass has a relation with the change of the direction of the intensity.

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The propagation paths of the vibration that generates in the mechanical structure are searched using the vibration intensity defined as "the vibration energy that passes through the unit cross section and the unit width in the unit time". Excitation sources are also identified. Propagation paths of different type such as the straight type, the meander type and the vortex type are found in a thin rectangular plate. In order to make clear the generating mechanism of the propagation paths, phase relation in natural mode between the excitation point and the damping point is investigated.

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This paper is concerned with the hysteresis compensation based on an inverse Preisach model. The inverse Preisach model uses the inverse function constructed from the function of Preisach model. Using this method, we can compensate hysteresis of GMM and calculating speed can be fast. We confirmed the effectiveness of this method by simulations and experiments.

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Miniaturize mechanical or electric products need to be produced at a reasonable cost. Production of micro parts encounters several problems, such as chemical reaction, microstructure dependency which are obtains negligible at nano machining. This research aims to develop a micro-lathe, which enables to in-situ observe cutting behavior, and influence of microstructure dependency as it is installed inside SEM. This paper has described the details of micro-lathe, and the primary cutting test.

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In order to meet the demands of high integration in electronic and optical applications, mechanical micro-machining technology [1,2] has been progressing rapidly in recent years for its 3D accessibility to a variety of materials. Newly developed in this research is a multifunctional machining system capable of micro- milling, turning, grinding, buffing, polishing, EDM, ECM, laser machining and their combinations. This paper reports design and development of the system and its application in micro lens mold fabrication.

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MEMS is getting a lot attention in processing micro devices. But, these processing is limited to mass production and structure. So, micro machining is reconsidered because that is efficient way to process three-dimentional shape, to make complex structure. The propose of this investigation is to analyze the effect of material's inhomogeneity in carbon steel and size effect on the shape, accuracy of dimension, machinability. Micro scratching test is one of the methods to analyze these phenomena. This paper reports on the results of micro scratching conduct on the S25C and the effect of α-ferrite's plastic flow in pearlite.

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Since this results in effects of both higher surrounding pressure and higher oxygen concentration, we tried to examine independently the effect of each factor on ignition delay shortening at higher surrounding air pressure. Experimental results showed that increase in oxygen concentration at constant surrounding gas pressure resulted in a drastic decrease in ignition delay, and increase in surrounding gas pressure at constant oxygen concentration resulted in a slight increase in ignition delay below the gas temperature of about 900K.

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The ignition lag of dimethyl ether (DME), ethane and propane at equivalence ration of 0.2,0.3 and 0.4 were measured by the use of rapid compression machine (RCM). As a result, the ignition lag of ethane and propane are affected by the equivalence raio, on the other hand, the ignition lag of DME is not affected by the equivalence ratio. This results is consistent to that of numerical calculation result based on Currun's chemical kinetics model.

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Low fuel consumption and high combustion efficiency are being demanded on automobile manufactures so that CO2 can be reduced on global scale. Gasoline direct fuel injection is effective on fuel consumption reduction by stratified lean burn operation. This paper reports on the study of a air-guide stratified charge combustion concept which consists of swirl type injector and tumble air motion. The new shape of spray was developed to reduce the effect of ambient pressure. Engine test results showed fuel consumption and NOx emission were reduced using the spray.

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This paper deals with numerical simulation of combustion reaction as the subject of a two-stroke cycle engine. The simulation uses scavenging efficiencies to consider the concentration of residual gases, and is carried out with a single cell. Fuel used the simulation is propane gas which is solved the mechanism of elementary reactions. As a result, the rate of heat release for [HCO+OH=CO+H2O] becomes most large in formulas of elementary reaction. Moreover, formation of CO2,such as [CO+O+M=CO2+M] and [CO+OH=CO2+H], also has large rate of heat release, and the rate of heat absorption is larger in [H+O2=O+OH]. On the one hand, residual gas decreases the combustion temperature, and simultaneously the reaction speed.

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This paper deals with penetration distance and mixture of gaseous fuel injected in a cylinder. The phenomena are visualized with schlieren method and analyzed. Momentum energy of gaseous fuel injected is smaller in comparison with it of liquid fuel. So that, a depression was manufactured on the piston head to smooth flow of injected gas. As a result, the injected fuel flow for cylinder head turning over at depression on the piston head, however a part of the injected fuel spreads widely on the piston head. It is considered that matching between shape of the depression and hollow-cone of injected fuel is important.

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This paper deals with a methane gas diret injection two-stroke engine supposed future natural gas engine. The characteristics of a two-stroke engine are high power and high torque from low revolution range. But general two-stroke engines have problems of air pollution due to HC emission at scavenging process, and consumption of lubrication oil. This two-stroke engine with poppet valves and direct injection of fuel was improved from a four-stroke engine to prevent fuel blowing through the exhaust valves, and to improve lubricating oil consumption and discharge. As a result of experiment, stable combustion and operation had be got, but enough power had not be got. For this matter, adopting high pressure fuel injection and modification of combustion chamber are considered.

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This paper deals with effects of Magnetic Fuel Improvement Device which is expected that the combustion characteristic may be improved by activated fuel and the exhaust emission may be purified by improved combustion. The fundamental idea is based on that the fuel ingredient flowing in magnetic field must get electrical energy according to "Fleming's right hand low, " and the electro energy must activate the fuel ingredient by extinction of Van der Waals combination or cluster split. The effects were investigated with a diesel engine using light-oil according to JARI D-13 mode test. As a result of the test, we could not find clear evidence to prove improvement of combustion or purity of exhaust emission.

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We experimentally evaluate a performance and exhaust emissions of a four stroke direct injection diesel engine operating on water-fuel emulsions. Three types of water emulsified fuels of diesel fuel and biomass based fuels are produced after the suitable selection of emulsifier. The ratio of water to fuel oil was changed by volume from 0 to 30%. We use JIS # 2 diesel fuel, diesel fuel containing 50% volume waste food-oil (Blend 50), and soybean oil methyl ester (VDF) as tested fuels. The combustion characteristics and emissions such as NOx, CO, HC, HCHO, O_2,CO_2 and smoke are compared with the case of diesel fuel. We found that (i) the CO emissions of water-fuel emulsions are higher than diesel fuel especially in the low load range. (ii) the Nox emissions of water emulsified fuels are lower than diesel fuel in the almost load range, and smoke emissions of water-fuel emulsions is lower than diesel fuel. (iii) fuel consumptions of engine operating on water emulsified fuels are lower than original fuel in the whole engine operating range.

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Methane fermentation system has been developed for recycling specific organic wastes at local area. In this study, methane fermentation efficiency of mixed liquor between garbage and cattle waste can be examined. Results are useful to design methane fermentation plants adapting the change of composition of local area wastes. Another subject for the system construction is to reduce the burden of methane fermentation. Thereupon, developing the method that removes the nitrogen and H_2S from the treated water and biogas, it is wished to reduce costs and manpower of maintenance.

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An Engine Simulator for Variable Valve Timing System was developed. The simulator with the 1st-order scheme was used to calculate steady state engine performance. A good agreement was obtained between the simulation and the experimental results of engine performance. The simulator was applied to control intake and exhaust variable valve timing for increasing internal EGR. The engine test results with direct fuel injection system showed higher internal EGR rate reduce Nox emission.

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The performance of a horizontal axis wind turbine (HAWT) greatly depends on the performance of its airfoil sections of the rotor blade. This study is an experiment (using wind tunnel) to improve airfoil performance by boundary layer control with Vortex Generators. The experiments were performed in the range of Reynolds number from (10)^5 to 4×(10)^5 and attack angle from 0°to 24°.

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Recently, soil pollution with volatile organic compounds (VOC) is revealed. And quick purification of polluted soil is seriously required. This paper describes a result of clean-up experiment for polluted soil with trichloroethylene. Clean-up system consists of clod smashing machine, mobile type soil recycling machine (SR-P) and regenerative catalytic oxidizer system (RCO). This is suitable system for "Hot SOIRU" method of construction. Experimental results show that this system can purify polluted soil with trichloroethylene quickly, certainly and safely.

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Pre-straining effects on fatigue strength of TRIP-aided multiple phase steel was studied from microstructural viewpoint in order to evaluate fatigue reliability of mechanical product after plastic working process. Effects of pre-strain were examined by comparing two types of specimen : one was cut from 10% pre-strained TRIP steel sheet, the other was untreated virgin material. The pre-strained material ensured a 20% improvement in the fatigue strength over the virgin material. Both of pre-strained and virgin specimens were broken with ductile fracture appearance as well as uniaxial tensile fracture, Difference of fatigue strength between two types of materials was closely related to the deformation behavior during cyclic loading. The improvement of fatigue strength could be explained in the following factor associated with the microstructure of TRIP steel : (a) connected configuration of hard phase in microstructure, (b)γ-phase transformation induced plasticity be pre-straining, and (c) origination of compressive residual stress in α-phase by pre-straining.

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Since today's automobile body needs to be both lightweight and safe, the employment of high-tensile steel for automobile parts is increasing in the manufacturing industry. Therefore, the prediction and reduction of springback error has long been a key issue for obtaining accurate shapes and dimensions in forming automobile parts. In this study, we examined the new method of predicting the shape freezing property by combining V-bending test data with Finite Element Method (FEM) simulation results. This hybrid system will help to predict the shape and dimensions of parts in advance and to determine the bending condition corresponding to material type and press capacity.

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The symplectic semi-Lagrangian (SSL) method was developed in order to improve the preservation of physical quantities of semi-Lagrangian method. In the method, symplectic integrators are adopted in searching for the upstream point in the semi-Lagrangian method. The purpose of this paper is to verify the validity of symplectic Semi-Lagrangian method for a practical fluid problem, that is two-dimensional incompressible viscous flow. We compare here two kinds of implicit symplectic integrators; second-order gauss method and second-order trapezoidal rule method. The computed results show that the SSL can take such large time-step size over Courant number 1 without loosing computational accuracy. It also turns out that second-order gauss method is more accurate than the trapezoidal rule method.

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The purpose of this study is to confirm the effectiveness of symplectic time integrator, which has a good property of well-preserving Hamiltonian of system, in the discrete vortex method. The considered problem is two-dimensional Karman vortex shedding around a square cylinder. It is found from the numerical analysis that the symplectic integrator, the 4th order Gauss method, is superior to the 2nd order Euler method used in the previous study with respect to the preservation of Hamiltonian, lift coefficient and spectrum of vortex shedding.

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Parallel computing of finite element method was performed using the Hitachi parallel computer SR2201,and improvement in the speed of calculation by parallel-izing was attained. The technique feature is described below. (i) In the process which obtains the approximation solution in a finite element method, the calculation process of the solution of the simultaneous linear equations which are approximation equations was perceived, and parallel-ized processing based on line block partition of matrix was performed. (ii) Simultaneous linear equations are sparse matrix. So, CSR storage used for efficient sparse matrix storing. The calculation was accelerated and saving of a memory was enabled.

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Nonlinear partial differential equations system involves many constitutive correlations and input parameters that are subjected to uncertainties. We often need the sensitivities of these parameters to evaluate the computed results. A generalized sensitivity analysis method has been developed by D. G Cacuci since 1981,which method uses adjoint system of the original one differentiated with regard to system parameters. We applied this method to an advection-diffusion equation, as a first step, to develop a comprehensive sensitivity analysis system for environmental problems.

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In recent years, technologies to manufacture high cost performance products in shorter periods of time have become considerably necessary in the manufacturing industry in general, to meet drastic changes in the market needs and the reduction of development cost. In response to this trend, our corporate facility actively makes use of computational fluid dynamics (CFD) analysis in studying fluid flow in turbomachinery such as pumps, which are our main products. This report introduces an examination of the prediction of pump cavitating performance by using CFD code

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In the deformation analysis of the circular plate subjected to pressure, the fundamental differential equation system is derived by applying a finite deformation theory. We formulate the finite element formulation from the fundamental equation by applying the weighted residual method. By numerical calculation, the differences between the plate solution based on the linear theory and the present solution are shown. Furthermore, it is also shown that the present solution approaches the membrane solution along with the incrementation of pressure.

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