Using Monte Carlo simulation technique, we present a numerical result of a geometric surface model for anisotropic membranes. The model is constructed on the basis of Finsler geometric notion. In this model, the bending rigidity and the surface tension become position-dependent and direction-dependent. We see a multitude of anisotropic phases such as a tubular phase, a disk phase and the spherical phase in this model.

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We study a heterogeneous surface model with many rigid plates by using the canonical Monte Carlo simulation technique. The rigid plates on the surface are assumed as an analogue of heterogeneous components in membranes. We calculate the string tension σ by fixing two rigid plates on both ends of the surface. These two rigid plates are separated by a distance L. We find that the relation between σ and L is considerably different from that of the model without the plates. This result indicates that a mechanical property of heterogeneous membranes is different from that of homogeneous membranes.

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MEMS and NEMS are very-small devices that are created by semiconductor process technology. Their small size and light weight characteristics are attractive for space application, however, the radiation induced micro-defects tend to be created in space, and those influences should be larger due to their small size, therefore, it is important to investigate the micro-defect effects for precise evaluation of MEMS and NEMS durability. In this study, we performed molecular dynamics (MD) simulations for single-crystal silicon. As a result, we were able to reproduce the behavior of silicon as brittle materials, and we were able to assess the influence on material properties and strength due to micro-defects.

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It is required that assessment of tsunami for the power plant equipments along the coast after the 2011 off the Pacific coast of Tohoku Earthquake. The existing method has a problem that the floating objects are outside of scope. This study addresses the problem, and the flow is developed to evaluate the effect of tsunami and the resulting floating objects by using tsunami runup analysis. The flow enables us to perform detailed assessment of tsunami. Moreover, the screening method is constructed to judge the floating objects.

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We analyze the solidification process and microstructure of Copper-Iron alloy by using phase-field method. We show that the crystal grain size of iron is significantly influenced by cooling rate and composition of the alloy system. By using this method, we can easily understand the formation process of the alloy microstructure and evaluate various process conditions.

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In the safety design field, the design-by-analysis that evaluates structual safety and reliability using FEM has been adopted. Welding deformation and residual stresses estimation methods based on the inverse analysis of eigen-strains are now being developed. Toward establishment of them, a priori information for solving the inverse problem and ensuring uniqueness of the solution are required. In this study, we focus on estimating optimum unknown parameters that have been determined heuristicly in the previous studies for neumerical stability of the inverse analysis to estimate eigen-strain accurately.

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Recently, bonded structure is used for many machine parts and electronic components. But, it may cause stress concentration near the corners. This leads to a decrease in strength, and reliability is lost. Therefore, it is necessary to evaluate the stress characteristics at a vicinity of vertex in bonded structures. There is stress singularity parameter to evaluate the stress characteristics. The stress state of a junction interface can be known by analyzing this singularity parameter. In this paper, stress characteristics in the junction interface of anisotropic bonded structures are analyzed by finite element method. As a result, the influence that the joint angle gave to the stress characteristic is clarified.

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When analyzing the strength of large structures, the stiffness of the contact surface might significantly affect the numerical results. However, it is not easy to estimate the contact stiffness with sufficient accuracy. If the contact stiffness of the structure can be estimated as an inverse problem by measuring the surface deflections, it is possible to precisely evaluate the stress distribution in service condition. In this papaer, supposing a FE models of a structure of which surface displacement are known at several nodes, a finite element approach to estimate the contact stiffness as an inverse porblem is conducted by modelting the contact stiffness as groups of one-dimensional spring elements. A built-up beam with the contact surface supported by multiple spring elements is analyzed, and the relationships between the surface deflection and the contact stiffness are quantitatively evaluated.

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Extended finite element method (XFEM) is analysis tool that specializes in crack analysis. Studies on the elastic problem have been carried out until now. On the other hand, analysis considering the elasto-plasticity problem is needed in the actual engineering problem. The problem with elasto-plasticity analysis using the XFEM is how to set the enrich function to the node of the vicinity of the crack tip. It is also one candidate to use the asymptotic solution of the displacement field of near the crack of a two dimensional elastic body as an enrich function. In this study, using this asymptotic solution for elasto-plasticity, we evaluated its effectiveness.

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We have developed the parallel CFD code for compressible multiphase flow using the HSMAC algorithm on GPGPU systems. In this paper, we checked the effectiveness by solving an underexpanded jet problem. As the results, we have achieved 14 times faster computation on the GeForce GTX570 than that on the Intel Core 2 Duo CPU(3 GHz).

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In the gas circuit breaker, the SF6 gas, one of the greenhouse effect gases, is used for instantaneously intercepting the circuit and protecting the instrument when an abnormal current like lightning flows to electric power transmission line of high voltage transformation installation. Recently, CFD approaches for gas circuit breaker designing become important because of need to reduce the SF6 consumption. In this study, we numerically analyzed three-dimensional behavior of the high temperature SF6 gas in gas circuit breaker using CRIMSON(Civa RifIned Multiphase SimulasiON) with taking account of electric arc heating between fixed electrode and movable electrode.

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Elbow ligament damage is an injury to often occur when doing sports, especially baseball or golf, with the arms and hands. When the ligaments are damaged and its functions are limited, the large influences must be given to the activities of daily living. In this study, we made a three-dimensional model of the human arm that consisted of the bones and the ligaments from CT images, and simulated the deformation of the elbow ligaments during the flexion of the elbow. From the simulation results, we obtained the stress distribution and the deformation in each ligament.

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We develop simulation software, in which the Object-oriented Modeling is employed in order to represent its autonomous and distributed character. The simulation including the effect of player's eye-sight indicates that players fail in passing within 15% at least even though they have good ability for their sight, and actual statistical data of world-famous clubs support the present result. It is also found that too wide sight of a player tends to increase pass failures. Furthermore, reproducing the typical formation in soccer-play, the evolution of the formation is investigated. As the result, formation of 4-4-2 adopted currently shows the superiority to other formations, which means the evolution of the formation up to the present is quite valid.

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Accurate measurement of the aerodynamic coefficients for a soccer ball in flight has been difficult yet since some mounted support has to utilize in wind-tunnel experiments. In the present study, we attempt to estimate the aerodynamic coefficients for a soccer ball by using both measurement and simulation. The trajectory of a ball is recorded with cameras, from which the initial angle and the height are determined. Also, the initial velocity and the flight distance are measured with speed guns and a measuring tape, respectively. Since simulation with the measured initial condition and aerodynamic coefficients calculates a trajectory, we can find the coefficients that minimize the error between the measured and simulated values in height and distance. The estimated results show that the lift-drag ratio of a soccer ball lies in near 1.5 or 2.0.

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This paper investigates a new constitutive model of the competitive swimwear considering stress-softening. The fabrics for competitive swimwear show nonlinear elasticity regarded as hyperelasticity and they have an anisotropic characteristic which is dependent on the directions of warp and weft yarn. In order to reproduce these properties numerically, hyperelastic model considering anisotropy was produced. In addition, they present a loss of stiffness after first loading of cycle loading test. This phenomenon depended on the maximum deformation previously reached in the history of the material. A stress-softening model using stiffness relation of first loading and second loading was proposed. Cyclic loading tests were conducted and the applicability of the model was verified.

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The purpose of this study is development of a new design method for competitive swimwear by numerical simulation. Biaxial tensile loading tests were conducted to obtain the mechanical characteristics of competitive swimwear. The fabrics of competitive swimwear consist of chemical fiber. From biaxial tensile loading test results, the fabric has orthotropy and the stiffness of the fabric shows the graph like the two polygonal lines along with the increase of stretch. An anisotropic hyperelastic model was applied to the reproduction of mechanical characteristics of swimwear. The anisotropic hyperelastic model in this paper is able to adjust the axial and shear stiffness individually. Finite element simulation of tensile loading tests was conducted to show the applicability of the anisotropic hyperelastic model to competitive swimwear. The results of the simulation showed good agreement with that of tensile loading test. It is important to design a pressure given by stretch of competitive swimwear from the two viewpoints, the exercise performance and the burden to the heart function. FE simulation of the pressure using a cylinder model was conducted to show the applicability of our design method to competitive swimwear. The results of the simulation showed good agreement with that of pressure test in a practical range of competitive swimwear.

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The crack identification in a structure is the most important problem in securing safety. We have succeeded in identifying the position and the length of the crack in a plate using natural frequency changes and the Mahalanobis distance method. Mahalanobis distance method is a useful way of determining similarity of an unknown sample set to a known one. In this paper, to improve the identification performance, we employ both higher order natural frequencies and multiple sensors and then identify the crack by using the Mahalanobis distance method. We demonstrate that the presented method is very useful through experiments.

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In this paper, stresses of a hook bolt, anchoring railroad track on a railway bridge, are analyzed both experimentally and theoretically. When a train passes through on a railway, dynamic load act on hook bolts which is settled to fix a rail to a sleeper. Thus, repeated passing of the train may cause fatigue fracture of the hook bolt. To analyze the stresses of the hook bolt under the dynamic loading, caused by the train, is crucially important for the security of the train operation. In our study, we measured the stresses of the hook bolt by putting the strain gauge on the bolt specimen. And performing the elastic-plastic FEM analysis, we simulate the stress distribution of the bolt. Both the experimental and the FEM results are compared and the the stress distribution of the hook bolt is clarified.

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In this paper, an analytical solution for an infinite cylinder having an inclusion is given when the cylinder is subjected to tension at infinity. The solution is based on an approach involving Dougall displacement potentials and deduced using the simple forms of Cartesian and cylindrical harmonics. The boundary conditions on the surface of the cylinder and around the inclusion are completely satisfied with the aid of the relations between the spherical and cylindrical harmonics. The solution is shown in graphs and the effect of the inclusion on the stress distribution is clarified.

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First, static and dynamic compressive tests of an energy absorption element, which is made of an aluminum alloy, were carried out to estimate static/dynamic collapse force ratio at peak force and strain rate derived from strain history of strain gauges in collapsed zones. Next, static and dynamic tensile tests of its material were carried out to estimate static/dynamic stress ratio and strain rate. Finally, by comparing strain rate dependency of the flow stress between the element tests and the material tests, it found that the static/dynamic collapse force ratio of strain rate match to the static/dynamic stress ratio of strain rate.

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Recently, it is reported that electromigration failures occur in flip-chip solder joints because of joint structure miniaturization and high-density packaging. However, growth behavior of electromigration void in solder joint is not clarified. We observed the void shape of micro-solder joint with high degree of accuracy by using the synchrotron radiation X-Ray microtomography in SPring-8 in order to clarify behavior of electromigration void in solder joint. Moreover, we found that the failure life of Cu-cored solder joint was about 4 times as long as the life of conventional joint, and we clarified long-life mechanism of Cu-cored solder joint.

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Functionally graded material, FGM is a composite material composed of component materials. FGM is expected as a heat-resisting material. In the present study, FGM composed of Ni and ZrO_2 were manufactured to reduce curvature and delamination by powder molding method. Vickers hardness test, microstructure observation and radius of curvature measurement and creep rupture test were carried out. The following results were obtained from the tests. The chemical composition of ZrO_2 side should be changed in small increment in order to prevent the curvature and delamination. The creep rupture strength of Ni- ZrO_2 FGM was strongly dependent on radius of curvature compared with the density.

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The formula of SiO_2 static fatigue crack growth behaviour based on atomistic model is extended to take the effects of pH into account. The curves expressing the relationship between crack velocity and stress intensity factor are obtained from the calculation for three differenet pH values, 1.8, 6.3 and 12.2. The calculated results coincide well with experimentally obtained results.

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There are numerous cases where a volumetric flaw has found near a piping branch in-service. Because the stress concentration at a piping branch intersection under internal pressure and/or external moment is always larger than that of a straight pipe, it is strongly necessity to establish a quantitative and reasonable plastic collapse assessment procedure. In this paper, a new assessment procedure for a piping branch with a volumetric flaw was proposed. The plastic collapse load predicted by the proposed assessment procedure isverified by the result of the nonlinear FEA.

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Some general industrial pressure vessels are working in the condition under high temperature and pressure with hydrogen for a prolonged time. The hydrogen assisted cracking property of low-alloy steel was clarified experimentally. This paper proposes the way to determine the threshold stress intensity factor by using electric potential drop method.

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We study the strength and fracture evaluation of the plastic material subjected to different loading configuration. Four loading configuration and notch effect of material testing considers as follows: a)Tensile test, b)Bending test, c) Charpy impact test, d)Fatigue test. The present paper describes a method for evaluating the mechanical strength properties from the material testing and fractography The load deformation characteristic propensity of the acrylic resin free of the influence of material testing method and notch effect. And we consider that look at the link between strength properties and fractgraphy

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The crack tip opening angle (CTOA) is a viable ductile fracture and may be possible to use for elastic-plastic, crack propagation analysis without the constraint of LEFM. This paper reports each correlation between CTOA and the stress intensity factor (K) in stainless steel (SUS316), single edged notch bend (SENB) specimens. The SENB specimens were cyclically loaded at various constant load amplitudes with a load ratio, R〜0.01. These parameters of the specimens were measured by crack gage and clip gage, during the fatigue crack extension. As a result, relationships of each parameter show crack tip shape deformation is divided into two patterns of crack growth by the expansion of the plastic region.

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We study the load history effect on the plastic collapse load on the austenitic stainless steel piping subjected to combined axial force and torsion. Three loading patterns considers as follows: a)Torsion load followed by Axial force load, b)Axial force load followed by torsion load, c)Simultaneous load Axial force and torsion load. The present paper describes a method for evaluating the collapse load from the Axial direction stress - displacement and shearing stress - rotation charts. The compression evaluation plastic collapse load bigger than the tension evaluation plastic collapse load of the austenitic stainless steel piping follows von Mises yield surface regardless of load history.

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Analysis for natural convection heat transfer between parallel flat plates was conducted to develop a thermal insulation system. The heat transfer and fluid flow were analyzed to develop an optimum thermal insulating architectural structure. The optimum vent layer size and the optimum cross-sectional shape of thermal insulation system were investigated with the numerical simulation. The vent layer size and the cross-sectional shape were considered along with developing the technique how to control the present thermal system by switching the vent.

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The present study focuses on the turbulent natural convection heat transfer in an enclosed rectangular container having high aspect ratio. The container is composed of the heated and cooled plates. The working fluid is air when the value of Rayleigh number is small, and is water when the value of Rayleigh number is large. The numerical simulation is investigated at the same time in order to elucidate the experimental results. It is obvious that the numerical computation and the empirical investigation are well correlated with the heat transfer correlation proposed previously.

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The thermo-physical properties of Ferrite Fluid(MSG-W11) which is a liquid that reacts to magnet are elucidated in order to consider the temperature dependency. The values of thermo-physical properties such as density, viscosity, specific heat, thermal conductivity and thermal diffusivity are measured experimentally and quantitatively. The heat transfer of natural convection is also investigated in a horizontal enclosed rectangular container filled up with Ferrite Fluid(MSG-W11) under the conditions of undersurface heating and upper surface cooling

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Low-speed up-flow is generated due to the water radiolysis in the spent vessel used by contaminated water treatment facility of Fukushima Daiichi Nuclear Power Plant. Though it is important to understand the inside flow of the vessel for storage, it is not clear. Thus flow test was performed with a simulated acrylic cylindrical vessel. This paper reports results of visualization of low-speed upflow in a cylindrical vessel by using LASER light sheet and high speed camera. It was confirmed that stagnant flow was generated around the stepped section, and the stagnant flow repeated appearance and dissipation. It was also found that the behavior of the stagnation depended on gas flow rate.

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A numerical lifting line method is proposed in order to study the Reynolds number effects on the aerodynamic characteristics of each wing in a solo flight or formation flights. An Oseen vortex model is used as the damping trailing vortices from a wing. The solution of this method is hard to converge, and then this requires to adopt a few techniques in the calculation processes. This method can calculate the lift and induced drag distributions on each wing and the up/down-wash distributions around each wing at arbitrary Reynolds number. The aerodynamic characteristics of wings in formation flights are remarkably influenced by flow viscosity under Re=10^4.

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Ethanol oxidation mechanism proposed by Marinov was validated in the pressure range 2.6 to 2.8 MPa, the temperature range 882 to 977 K using a rapid compression machine. Equivalence ratio was set to 1.0 and 0.25. As a result of changing the parameters of the rate constant of (R1) which was high sensitivity on the temperature at the time of ignition, simulated ignition delay time was improved. Although the difference of ignition delay time for φ=0.25 and experimental results were longer than that of φ=1.0, the improved model reasonably predicted the experimental ignition delay times.

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Influence of Hydrotreated Vegetable Oil (HVO) blend on cloud point and pour point of diesel fuel was investigated. Cloud point and flow point measurements were conducted in accordance with JIS standard. As the result, it was experimentally confirmed that cloud point decreases in proportion to the HVO amount blended in diesel fuel. The pour point rises as HVO blending ratio increases. At the ratio of 50wt.% blending, the pour point reaches a maximum, the same level of pure HVO.

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Primary standard for small flow of liquid hydrocarbon was developed at AIST and recently its calibration capability was upgraded to include volumetric flow range of 0.01 m^3/h 〜 0.1 m^3/h and kerosene as one of the working liquid options. The best calibration and measurement capability (CMC) is estimated to be 0.064 % for volumetric flow rate and 0.020 % for mass flow rate (coverage factor: k=2). In-house comparisons between small and medium hydrocarbon flow facilities at AIST were carried out, using servo PD flowmeter and Coriolis flowmeter. Calibration results by Coriolis flowmeter showed a good agreement between the two facilities. However a certain discrepancy was found in the calibration results of servo PD flowmeter between the two facilities. Clarification of the discrepancy is being discussed in detail in the paper.

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Radiative characteristic of N_2-CO_2 mixture afterglow plasma generated by microwave discharge changes by mixture ratio of N_2 and CO_2 gases. In order to investigate the cause of the change, the electron temperature and electron density were measured using triple probe method. The triple probe was inserted in the afterglow plasma and was set at 10mm intervals at the point of 40 to 100mm from the downstream end of the cavity resonator. From the measured probe voltage and current, the electron temperature and density were calculated. The profiles of the electron temperature and density were changed by the mixture ratio of N_2 and CO_2 gases. For the CO_2 mixture ratio of larger than 6%, the electron temperature and density decreased steadily along with the flow, however, for the CO_2 mixture ratio of less than 4%, increased temporarily in the lower region of 50 to 90mm.

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Numerical simulation method to analyze unsteady flow phenomena in the upper plenum and the hot-leg piping system in Japan Sodium cooled Fast Reactor (JSFR) has been developed. As one of the most significant issues related to unsteady phenomena, a flow-induced vibration (FIV) in the hot-leg piping with the short elbow (curvature radius corresponds to diameter) is mainly targeted in this study. At the first step of the simulation model development, models of the hot-leg piping with the short elbow integrated into a symmetric half domain of the upper plenum were constructed. Through the numerical simulations in the half sector model, applicable numerical schemes and turbulence model were confirmed and requirements of mesh arrangement for the transient calculation for unsteady phenomena analysis were revealed.

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In Japan Atomic Energy Agency (JAEA), a study of the thermodynamic feasibility of straight-tube steam generator for Fast Breeder Reactor has been conducted. A multi-channel computer code to analyze thermodynamics and flow stability in water-side of steam generator was developed with drift-flux model. The computer code was validated by the simulation of flow instabilities in two parallel channels and comparison with experimental results. The capability of flow simulation in multi channels was confirmed by the simulation of flow instability in 401 parallel channels. Parallelization for the multi-channel analysis code with MPI was performed in order to increase the computing efficiency, and the parallelization efficiency was confirmed.

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Ultra-high speed and magnified observation of DME spray was carried out in a constant volume vessel on CI engine-like pressure and temperature condition to understand break-up and evaporation characteristics of DME spray. High-resolution diffused back-illumination images were taken by a high speed video camera at frame speed up to 210,000 fps. As the result, it was found that droplet of DME spray is much smaller than that of diesel fuel, and evaporates at a faster rate. Atomization process through consecutive breakup of droplets, which is commonly found in ordinary diesel spray, is not a major in DME spray.

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This paper proposes new type of compressor that can deliver the air alternative directions. This compressor is made by replacing the location of inhalation/exhalation air port into proper position of ordinary vane type air compressor. This compressor can select the direction/speed of cylinder by changing the clockwise/counterclockwise rotational direction and the rotational speed of compressor and does not need an/the extensional solenoid valve/s. In this report, we choose components of this compressor. The air motor that composes this compressor is paid to attention, and a new sample is examined. Furthermore, we compare electrical power consumption that this system and standard system having the solenoid valve/s.

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Now, MAV (Micro Air Vehicle) that mimic a dragonfly's flight is being researched, because, dragonflies have high flight performances. In order to develop MAV that mimic a dragonfly's flight, it is important to investigate the aerodynamic characteristics of the micro spikes on a dragonfly's wing vein. However, the concrete effects of micro spikes have not been understood. In this paper, artificial wings with micro spikes that mimic Dragonfly's wings were prepared. Moreover, we experimented to investigate the aerodynamic characteristics of their wings. We found that micro spikes generated strong vortexes. As a result, we clarified one end of the flight mechanism of the dragonfly which did not become clear until now.

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This paper describes the numerical analysis and experimental equipment of two-phase nozzle flow, which is commonly applied to ejector of air-conditioning system. Two-phase flow nozzle is a device that converts thermal energy to kinetic energy. Gas and liquid have different properties, especially density. So the flow acceleration and velocity are varied and it is called velocity slip. It can cause energy losses. The efficiency of nozzle can be increased by reducing this phenomenon. In order to overcome this phenomenon, it is needed to analyze the microbubble in the nozzle of supersonic two-phase flow. It is predicted that microbubble is effective because of its properties. The main content in this paper is the comparison of analytical data by using STAR-CCM+ and practical data for supersonic two dimensional microbubble flows.

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In general, MOX materials are made from radioactive liquid which contains used nuclear fuel through denitrifying process. In this process, there's possibility that radioactive liquid will spout out from the vessel by dangerous boiling. Therefore it is necessary to appreciate mechanism of geysering phenomena and influence of the shape of evaporator and heating condition quantitatively in order to prevent from an accident. We studied about geysering phenomena in a vertical circular tube; D=30mm, L=1000mm, using water as working liquid. The mechanism of the geysering phenomena as seen from the temperature distribution of the working liquid along the vertical tube and pressure fluctuation were considered.

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Forced convection boiling of binary mixture fluid in a horizontal small tube, ID=1.45mm, and 100mm of heating length using Ethylene-Glycol/Water mixture is conducted to check the effect of the boiling heat transfer and pressure drop and quality, and to consider measured values with correlation. Pedicting pressure drop using the correlation at pure water and proposed with the tube diameter of 1.45mm, it became about 20% of error at the maximum. Prediction value at binary mixture less than 20% except that error increase at low heat flux. Local heat transfer coefficient of EG/water mixture gradually decreases. Kandlikar correlation was predictable heat transfer coefficient of water about 50% of error.

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An effect of nozzle-bucket axial gap length on the unsteady force was studied by using new method to predict the unsteady force which is induced by potential field and wake interactions between nozzles and buckets of steam turbines. The new method can separate the unsteady force into two components due to potential field and wake interactions, and the effect of nozzle-bucket axial gap length is obtained. A simple relationship between the nozzle-bucket axial gap length and the unsteady force was found to give easy and reliable prediction of the unsteady force.

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A hydraulic turbine for an open channel can generate power at low head and doesn't affect the environment because it doesn't have incidental equipment. However, because the rotational speed is low, the hydraulic turbine outer diameter becomes large. Therefore, an axial flow hydraulic turbine with collection device, using kinetic energy of open channel flow, is proposed. The performance and flow field of impeller only, collection device only and combination of impeller and collection device were clarified. It was checked the speed increasing of collection flow in collection device by analysis result of collection device only and analysis result of output of combination of impeller and collection device is larger than analysis result of impeller only.

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In a miniature turbopump, high speed rotation is required to accomplish required specifications for turbopump of the rocket engine. However, high speed rotation causes cavitation on impeller. In this paper, pump performance, the internal flow and characteristics of cavitation of two impellers with different blade angle were examined numerically. In addition, visualization of internal flow in non-cavitation and cavity on impeller at occurrence of cavitation were subjected by CFD. As a result, back flow at inlet of the impeller was occurred strongly by increased blade angle. Furthermore, conditions of occurrence of cavitation of two impellers were confirmed, and it became obvious that back flow at the inlet of impellers affected the characteristics of cavitation occurrence.

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