The CIVA method debeloped by Tanaka is a highly accurate interpolation method for complex shape such as triangles and tetrahedronsmesh. For apply this method to tetrahedral mesh, there are two interpolation techniques. one is a technique of using node that composes the cell. Another is a technique of using the tetrahedron constituted from gravity point of cell. In this study, we check accuracy of these interpolation techniques.

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Homogeneous charge compression ignition (HCCI) engine can decrease both NO_x and PM. However, it is difficult to control the ignition timing and the operating range is limited by knocking. The objective of this study was to increase indicated mean effective pressure (IMEP) of HCCI engine by energy accumulated type variable valve timing (EAVVT) system and supercharger. A numerical calculation based on an elementary chemical reaction model was conducted to estimate the effect of intake valve close (IVC) timing and supercharging on HCCI combustion. As a result, maximum IMEP increased from 0.32MPa to 0.51 MPa due to increase supplied energy without knocking. The reasons of increase supplied energy were that equivalence ratio decreased with supercharging, and that most mixtures were burnt at the expansion stroke with IVC timing control.

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Variable valve timing systems is paid attention for its ability to control homogenous charge compression ignition(HCCI)combustion. In this study,3-dimension Cam Type Variable Valve Timing(3DVVT)system; anew type of mechanical variable valve timing system was developed based on numerical analysis using detailed chemical kinetic reaction model.3DVVT system was applied to a single cylinder diesel engine to control HCCI combustion. HGCI combustion control becomes possible since the in cylinder temperature can be controlled by changing effective compression ratio. As a result, ignition timing was continuously controlled from BBDC21℃A to BBDC19℃A by 3DVVT system.

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Palm oil is thought to be one of the promising biodiesel which could be used in Japan because large amount can be imported by low cost, however palm oil and PME have poor low temperature fluidity. In this study, we clarified the solidification pressure of PME, and we attempted to improve the low temperature fluidity of palm oil and PME by blending JIS NO.2 diesel fuel, ethanol, and DME. As the result, PME solidified at pressure of 83MPa at 25℃. The low temperature fluidity of PME improved when diesel fuel, ethanol, and DME were blended. DME especially had high effect on low temperature fluidity improvement. The solidification pressure of PME was managed to raised to 145MPa by blending 10wt% of diesel fuel and ethanol at 30℃.

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The effect of NO doping on high temperature reaction (HTR) was examined. Numerical analysis based on detailed chemical kinetic reaction model was conducted for methane Homogeneous Charge Compression Ignition (HCCI) process as the representative of the HTR. The calculation results were verified experimentally using a single cylinder HCCI test engine. As a result, NO had advance effect to ignition timing of Methane. The mechanism of methane oxidation was found to be summarized. The effect of NO was that supplied reaction field with OH. (NO+HO_2=NO_2+OH and NO_2+H NO+OH.) Ignition timing of methane was advanced because of OH.

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It is necessary to change the fuel crude oil to a renewable fuel because the problem of global warming and oil resource depletion. Therefore, the high thermal efficiency engine operated by a renewable fuel is expected. Furthermore, the exhaust energy is should be used for high thermal efficiency. In this report, the concept of the reforming the fuel DME by using the heat of exhaust gas for spark ignition engine is proposed. The thermal efficiency based on the numerical calculation shows a increase the thermal efficiency about 12%.

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Lean combustion is known as a method to have a high thermal efficiency of spark ignition engines. However, the lean limit of gasoline is narrow and a performance of three way catalyst for NO_x reduction is deteriorates. The lean limit of Hydrogen is very wide. In this experiment, the effect of hydrogen addition to the gasoline is investigated. The experimental results show the increase of the brake thermal efficiency and the decrease of NO_x emission because of lean mixture operation of hydrogen and gasoline.

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Dimethyl ether(DME)can be used as refrigerant because it has a property to liquefy easily at roomtemperature,0.53MPa. In this report, using DME as a refrigerant is numerically evaluated by a comparisoncoefficient of performance(COP)at standard refrigeration cycle and single or double stage compressionrefrigeration cycle at-30℃ between a DME refrigerant and conventional refrigerants. The results showedthat the DME refrigerant is superior as compared with conventional refrigerant in term of COP at standardrefrigeration cycle.

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Homogeneous Charge Compression Ignition (HCCI) combustion has attracted considerable interest in recent years as a new combustion concept for internal combustion engines. The HCCI combustion process has four issues to be resolved: ignition timing control, slower combustion reaction rate (maximum heat release rate), difficulty expanding stable operation to the high load region and avoidance of knocking. In this study, an attempt was made to overcome these issues by applying external exhaust gas recirculation (EGR). External EGR rates were varied and examined their respective influence on HCCI combustion.

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Gas-liquid counter current flow is a flow pattern where gas and liquid co-exist and are flowing in the opposite direction. This affect happens when LOCA (Loss Of Coolant Accident) occurs in the light-water reactor. Elucidation of the mechanism of this affect is needed to perform the cooling of the core enough. In this study, I assume the situation that water level was formed by a limited coolant. A purpose of this study is to elucidate this phenomenon from an aspect of the air bubble secession. About water level, I tested it by three patterns of 50mm, 100mm and 200mm.

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The purpose of the study is to experimentally examine heat transfer characteristics of propylene glycol solution. Experiments were performed on a platinum wire, 0.2mm in diameter, as heating surface at saturated and atmospheric conditions for concentrations from 5 to 40%. It was found that as increasing propylene glycol concentration, the wall superheat becomes higher, the critical heat flux and the heat transfer coefficient become lower.

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Aparallel looped thermosyphon is newly developed to improve heat transfer defects of a conventional thermosyphon. The purpose of this study is to evaluate thermal resistance of the new thermosyphon. In the experiments, the evaporator section is heated by circulating hot water and the condenser is cooled by cold water. The coolant temperature is 25 and 35℃, the hot water temperature changes from 30 to 80℃ and 40 to 80℃. The flow rate was held constant at 0.2 and 0.51/min. As a result, compared with the single tube thermosyphons, it is found that looped parallel thermosyphons has a lower thermal resistance by about 70%.

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To clarify the relation to the power generation of the fractal and the solar battery, the amounts of power generation when not using it in case of the case to use the fractal figure were compared in this research. The figure prepared two kinds (the Sierpinski carpet and Sierpinski gasket). In addition, each reversing figure was prepared and it experimented. The experiment measured the change in the amount of power generation while changing the complexity in the figure. As a result, it was clarified that the amount of power generation changed when the fractal figure was used

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The purpose ofthis study is resolving the influence ofrotor stage number on Savonius rotor characteristics.Torque coeffucient, power coefficient, velocity distribution and turbulence intensity ofthree kinds of Savonius rotor were measured with Reynolds number was 4.1×10^4 and tip speed ratio of velocity distribution and turbulence intensity was 0.2,0.4,0.6,0.8.Tip speed ratio of maximum torque coefficient and the maximum power coefficient became low as the rotor stage number increases. Turbulence intensity of two stages rotor was lower than one stage rotor and three stages rotor in y-axis. In z-axis, differences ofvelocity by the influence ofrotor stage number were not found.

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In this paper, we purpose to develop "Flow measurement device" using FBG sensor. This device is measurement device using drag of object and designed to exclude the effect of bending and adhesion. Moreover, this device has "Amplifier mechanism" using principle of leverage to amplify the output and "Conversion mechanism" to convert rotational motion into linear motion. To examine sensor performance, we conducted performance test using wind tunnel. In the result, we got unique output value in high velocity region and confirmed that this sensor is able to measure velocity and flow direction.

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In this Paper,I-V characteristics of direct DME fuel cell have been measured by the following condition. Anode Pt-Ru catalyst quantity is 1.0mg-Pt/cm^2, cathod Pt catalyst quantity is 0.2〜1.0mg-Pt/cm^2,operating pressur is 1.0,3.5ata, cell temperature is 120℃. In the case of cathode catalyst quantity change(anode catalyst quantity 1.0mg-Pt/cm^2), performance has been improved by catalyst quantity increase. The influence that change of cathode catalyst quantity gives to performance than change of anode catalyst quantity is small. About catalyst quantity reduction, performance has been achieved 0.1W/cm^2 of aim at cathode catalyst quantity 0.2mg-Pt/cm^2.

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Direct DME fuel cell (DDFC) has already known that power density is improved by using Pt-Ru catalyst at anode from past study. In this experiment that Pt catalyst of cathode had been 1.0mg-Pt/cm^2 of a fixed quantity. Therefore, in this study, anode catalyst quantity changed into 1.0, 2.0, 3.0mg-Pt/cm^2 and cathode catalyst quantity changed into 0.2〜1.0mg-Pt/cm2. In this condition, that measured power density, single electrode test, and the CV test.

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In late years, fuel cell vehicles (FCV) using hydrogen as the fuel have been attracting attention in terms of the reduction or CO_2 emissions. In the FCV, the hydrogen gas is stored in tanks and are covered with carbon reinforced plastic. that are lined with aluminum. However, it is known that in some aluminum alloys hydrogen embrittlement (HE) occurs. In this study, sheet specimens of a 7075 aluminum alloy subjected to three heat-treatments, under-aged (UA), peak-aged (PA) and over-aged(OA), were tensile-tested in a moist air as well as dry nitrogen gas by slow-strain-rate technique(SSRT). In addition, effects of the behavior of hydrogen has been investigated by means of thermal desorption spectroscopy (TDS), hydrogen-emission have been monitored by TDS test. The result of SSRT tensile tests indicated that the sensitivity to HE was the highest and lowest in the UA and OA specimen, The UA specimen deformed by 7% in the moist air as well as that without deformation was subjected to the TDS test, and it was found that the amount of hydrogen was increased by the deformation.

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Fuel cell vehicles (FCVs) are ideal in terms of solving the global warming problem. In the FCVs, high-pressure (35MPa) hydrogen has been being used as the fuel, being contained in a tank composed of 6061 aluminum-alloy liner and surrounding carbon-fiber-reinforced-plastics layer. Replacing the 6061 alloy by a high-strength aluminum alloy is demanded to increase the distance per a fuel supply by raising the initial pressure to 70MPa. In some high-strength aluminum alloys, however, hydrogen embrittlement has been reported when the materials are tensile-deformed in a moist air or the materials are cathode-charged with hydrogen. To confirm the safety of the hydrogen tank in the FCVs, investigation on the behavior of hydrogen followed by the study on the hydrogen embrittlement is needed. Hydrogen microprint technique (HMPT) has been known to be effective to investigate the behavior of hydrogen, in which hydrogen atoms can be detected as silver particles through a reaction between hydrogen atom and silver halide. Up to date, hydrogen invasion from the environment to the inside of the aluminum base materials as well as the hydrogen emission from the materials to the materials has been considered to be significantly affected by the surface oxide layer. To confirm this issue, in this study the effect of surface coating, ion-plating and vacuum-vapor deposition, on the behavior of hydrogen has been examined in a typical high-strength aluminum alloy, 7075, by means of HMPT. Sheet specimens ion-plated and vacuum-deposited both with nickel was charged with hydrogen gas of 2MPa with and without tensile stress above the yield stress on the coated-side surface, and HMPT image was observed on the uncoated-side surface. The ion-plated specimen had a larger amount of hydrogen emission than the vacuum-deposited specimen when tensile stress was applied.

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The 6061 aluminum alloys are being used as a liner material of a high-pressure hydrogen tank for the fuel cell vehicles. However, it is known that some aluminum alloys cause hydrogen embrittlement. Therefore, it is important to confirm the location and amount of the hydrogen that exists inside the material. To conduct this, thermal desorption spectroscopy (TDS) is regarded as an effective examination method. It is thought hydrogen in the material is trapped by dislocations during processing, and that the dislocations that trap hydrogen move (glide) accompanying the hydrogen atoms in the material. However, the relationship between this kind of hydrogen behavior and the hydrogen embrittlement has not been clarified yet. Thus, in this study, the behavior of hydrogen affected by cold rolling was investigated by means of TDS on a 6061 aluminum alloy together with a pure (99.99%) aluminum. The amount of emitted hydrogen decreased significantly by the cold rolling both in the 6061 and pure aluminum, implying that hydrogen atoms that are trapped by the dislocations move in conjunction with dislocation gliding during the cold rolling.

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The relationship between hydrogen absorption-desorption properties and crystal structures in La_2Ni_<6.9_x>Al_<0.1>Fe_x(O≦x≦2.1)were studied. The structure data was determined by x-ray Rietveld analysis. The unit-cell volume of La_2Ni_7 phase increases with increasing of Fe contents, On the other hand, the lattice parameter ration c/a decreases with increasing of Fe compositions. Desorption pressure was under 0.1 MPa and show flatness plateaus when the Fe contents more than x=0.7.However, the plateau region decreased drastically more than x=0.7. SEM images of samples were observed by FE-SEM. The micro-cracks on surface in Fe contained allays after hydrogenation were not detected.

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Electron temperature (T_e) and electron density (n_e) are most important parameters of plasma, respectively. However, increasing pressure around plasma, theoretical diagnostic will not fit for actual phenomenon because of electron-heavy particle and heavy particle-heavy particle collision frequencies rising. The UV and visible optical emission spectroscopy (OES) applied for Theoretical diagnostics toward He-plasma in the atmosphere. Relative emission line intensities of neutral helium are estimated for the principal quantum number n=3 to 2 transitions. The population density calculated from compare of the 6 spectrum with defined excitation temperature (T_<ex>) in internal partition function to estimate Te from Tex. The other method is based on Collisional-Radiative model (CRmodel) to calculate Te and ne. Moreover, gained gas temperature (T_g from OH・(306.4[nm]) emission line. In the result, n_e=1×10^9[cm^<-3>], T_e=1.8-2.4[eV] and T_g=400-550[K] on various apparatus conditions.

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To improve a tool life, nitriding to WC-C alloys was examined. The hardness at the surface of WC-Co alloys is revealed to increase by ion nitriding. The hardness increase becomes larger with increasing of cobalt volume fraction. This suggests the precipitation of nitride which is confirmed by nitriding to a pure cobalt bar.

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The nitriding-quenching invented by Inaba was applied to several kinds of steels. Approximately 100μm depth from the surface was commonly butruded except an Fe-17 Mn-6Si steel plate. High nitrogen bearing martensite evolved at the surface of ferritic steels shows high hardness of HV900, high compressive residual stresses near 300MPa and preferable corrosion resistance. The morphology of high nitrogen steel examined by EBSP is similar to that of high carbon martensite.

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To study the influence of chemical compositions and microstructure on oxidation behavior of rolled steels, new two experimental techniques are proposed: one is gradient sectioning observation with EBSP and the other is X-ray or neutron reflectivity measurement. Trials have been made for commercially available interstitial free (IF) steel and multi phase steel with transformation induced plasticity (TRIP). Because the latter TRIP steel bears some amount of Si, the oxidation behavior at an elevated temperature in air is different from that of IF steel.

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Fatigue performance and fracture behavior of low carbon and phosphorus-added low carbon steels have been investigated by plane bending fatigue tests at room temperature in air. For all steels, fatigue tests were carried out at a frequency of 1000 cycles per minute. After all mechanical tests, fracture surfaces were cut and examined using scanning electron microscopy to identify the fracture features. At any applied stress level, phosphorus addition further improved the fatigue life of LC steels, however, it decreased life from macrocrack generation to breaking. Cold working increased tensile strength and fatigue strength of LC and LC-P steels, however, it also decreased life from macrocrack generation to breaking, which of LC-P steels is more adversely affected. Annealing decreased tensile strength and fatigue strength of LC and LC-P steels, although, it increased fraction of fatigue limit per fatigue strength.

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Steel wires produced by severely drawing show ultrahigh strength and comparable ductility. Strength and ductility of such wires were examined by tensile test in liquid nitrogen. It is found that the wires fracture in a ductile manner showing dimple at 77K. The tensile strength is dependent on carbon concentration is steels but hardly on test temperature.

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The lower bainite and so called "hard bainite" that forms at very low temperature was critically studied. The in situ neutron diffraction during bainitic transformation was firstly performed and the carbon partitioning in austenite before bainitic transformation is suggested. The related microstructural features were studied by conventional heat treatments and microscopy observations.

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In this study, carbon steels(545C,SK105C)were kept constant austenitizing temperature(1200℃)and the cooling rate from 750℃ to 700℃ was changed. This cooling rate will give us the pro-eutectoid cementite and ferrite of large size. Then, the sample was cut off thinly using the wire-cut electric discharge machine and the surface of sample has been corroded with Kalling's reagent. It was able to get the sample that only the ferrite dissolved in reagent the pro-eutectoid cementite and lamellar cementite remain in sample. The voids made by resolving the pro-eutectaid ferrite have been observed by the use of Scanning Electron Micro-scope(SEM).

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In this study, magnetic characteristic of automotive high tensile steel sheet was measured. The material used JSC280E, JSC590Y, JSC780Y, JSC780T, JSC980Y and JSC1180YN. First of all, the magnetism of the material cut out was measured. As a result, magnetic flux density of test piece showed a tendency upper right. Then the change of upper and lower cutting side in magnetic flux density is larger than that of the part of surface. After that, tensile test was done. The center of test piece rises and magnetic flux density has risen most. Magnetic flux density increase rose rapidly when going up from processing rate 0% to 1.43%. It was changeless though the processing rate went up from 1.43 to 4.29%.

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In recent years, higher mechanical properties are being demanded in thin sheets of copper alloys with the miniaturization of electric and electronic parts. Above all, because the materials for connector are usually subjected to heavy bending, good bending properties are especially required together with strength, electrical conductivity, etc. In this study,, effect of texture on the tensile and bending properties of a Corson series copper alloy sheets was investigated. The alloy was melted, cast, hot-rolled to 12mm thickness, scalped to 10mm thickness, cut into specimen of 30×30mm, cold-rolled to 0.3mm, cut into test pieces of 30×10mm, solution-treated at 800℃ for 1h and finally aged at 480℃ for 3h. The test pieces ware cut in the direction where the angles between the longitudinal direction, tension direction and rolling direction are O°(Good Way), 22.5°,45°,67.5°,and 90°(Bad Way). Bending properties improved while shifting from Good Way to Bad Way. In addition, texture was observed with measuring method called Schulz reflection method. As a result, Cube and Cu texture were found.

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In recent years, lighter materials are prone to be demanded particularly in the field of transportation as a solution of global environment problems. Because aluminum has a relatively small density and high electric conductivity, 30% and 60% of those of copper, respectively, replacing wiring cable materials from copper to aluminum cause weight saving at the same electric conductivity level. However, the strength of aluminum must be improved by alloying etc. keeping its high electric conductivity when applied to the actual wire cables. Specimens of Al- l.lmass%Cu alloys with Zr up to 0.2mass% were induction-melted, continuously cast into a round bar of 8mm in diameter and then cold-drawn. Tensile test and assessment of the electric conductivity were carried out. As a result, tensile properties and work hardening behavior were not affected seriously by the Zr addition, while electrical conductivity was significantly decreased as the addition amount increased.

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Gum Metal is a newly developed beta titanium alloy, which has an ultra-low elastic modulus, high strength, sup erelasti city, superplasticity, invar and elinvar properties. In this study, microstructural change including texture change by annealing have been investigated on cold-rolled sheets of Gum Metal, Ti-36.3Nb-2.03Ta-2.88Zr-0.31O. The results obtained were compared with those of a Ti-15V 3Cr-3Sn-3A1 alloy, typical beta titanium alloy. In the cold-rolled sheets , development of (111)<001> and (001)<110> textures were observed in Gum metal and Ti-15V 3Cr-3Sn-3-Al, respectively. There textures did not change basically by an annealing at 700℃ for 30min, although slightly weakened. Optical microstructures in the cold-rolled sheets did not change markedly by the annealing, either. Thus , the two alloys annealed at 700℃ for 30min were deduced to be in the recovered state.

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The dynamic damper with flexible controller is designed as removable dynamic vibration absorber for the vacuum cleaner. This study purpose is reduction of vibration and noise for the vacuum cleaner to a target value. For the noise of vacuum cleaner, this paper adopts the solid borne sound from a motor of vacuum cleaner. We apply the dynamic damper with stiffness coefficient as adjustable parameter to vibration reduction. As a result, the peak of noise level and the over all value is reduced.

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This time, we verified it by using FEM of "Partial Coating Effect" that big effect of damping It was able to be achieved in the case to make it coat to all aspects by partially covering viscoelastic material that made the steel plate usually covered to all aspects in laminated steel plate to make viscoelastic material covered. The method of covering viscoelastic material did the analysis separately for two kinds of models. One is "Center Coating Model", and another is "Out Coating Model". When having analyzed it about each analytical model while changing coating width of the viscoelastic material, it reports because the result of the idea by an analytical model in a certain coating wicth as Partial Coating Effect was obtained.

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We have proposed a posture control method for a hopping robot. Feedback gains for flight and stance modes are obtained by solving a certain optimization problem for the posture stabilization. The robot has a crank mechanism and hip drive mechanism.

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We have proposed a walking method by giving the planned path to the hip angle of the biped robot. The model of this robot is simple compasses type with torso and has two actuators at the hip. The planned path is composed of a cosine wave form. By the proposed method, the robot has succeeded in stable walking.

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We have proposed novel posture control method for biped running robot. Feedback gains for flight and stance modes are obtained by solving a certain optimization problem for the posture stabilization.

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In this report, We propose the walking control method of biped robot with knee joint based on mechanical energy to stabilize walking. Firstly we introduce biped robot model and control method. And then we simulate the biped robot with knee by walking control and analyze simulation. we have ascertained by simulation that the biped robot with knee can have walked flat conditions by the walking control method.

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In 1784, George Atwood invented a device called an Atwood machine. We use it for the measurement of acceleration of gravity, but this device can originally change gravity to suffer from into an object by adding a difference to mass of an object to hang at both ends of a device. Therefore we produced an Atwood machine in this study and really experimented on a fall and performed the experiment that considered various factors such as the moment of inertia of a pulley in fall distance and fall time and inspected the acceleration that acted on an object. Furthermore, we examined possibility of observation of the physical phenomena of variety in the minute gravity bottom where we used this device.

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Recently, the automatic takoyaki machine, parts feeder, using mechanism for converting motion are developed and researched. The automatic takoyaki machine rotate the takoyaki on the metal plate by the vibration of the plate. The purpose of study are development of automatic takoyaki machine for weight saving and noise reduction on mechanism. The equipment for this study use voice coil motor(VCM) to vibrate metal plate. VCM is set from 2 orthogonal directions, and the plate is whirled by vibration from the VCM. Then, vibration condition is compared and evaluated to research the vibration condition that the ball is efficiently rotated.

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Torque and levitating force can be generated even if the skew is given to the rotor of the magnetic bearing motor. This phenomenon is confirmed to by Hanyu's research(1). However, it is difficult to control the rotor because of varying torque and levitating force. In this research, analysis is performed with a new model which changed the coercive force of a permanent magnet to 263[kA/m], the rotating current to 0.5[A], the width of the magnet to three times, set the skew angle as 15[deg]. The average torque and the average levitating force increased. However, it seems to be difficult to control the rotor now.

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The purpose of the study is to investigate high speed turbomachinery system stability. Unstabilizing force due to Thomas force induced by turbine is reduced system damping of critical speed. In this paper, high-speed turbomachinery system is modeled using FEM, and natural frequency and damping ratio are calculated by complex eigenvalue analysis, using the double QR method. For estimating unstabilizing force, torque generated by turbine blade is calculated by CFD, and calculated cross coupling stiffness from torque. System damping is reduced by cross coupling stiffness from complex eigenvalue analysis results.

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When the stress acts on the object, a minute temperature change is caused in proportion to the volume change. This phenomenon is called the effect of thermo elasticity. In this research, the temperature change of a metallic foil according to the load stress was measured by using this effect as an application of infrared stress measurement method. The material of the foil used three kinds (the advance, aluminum, and copper). As a result, temperature change could be caught from 0.03[x] to 0.13[x]. In addition, the temperature change of all the foils was proportional to the load stress.

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High power spallation targets for neutron sources are being developed in the world. A mercury target is being installed in the material and life science facility of J-PARC (Japan Proton Accelerator Research Complex. The mercury target is subjected to pressure waves caused by a proton beam bombardment. The pressure waves load macroscopic stresses on the target vessel and induce the cavitaion in mercury through the pressure wave propagation processes. When cavitaation bubbles collapse, the localized impact damages so-called pitting damage, occur on the target vessel. The target vessel is subjected to the pitting damage and macroscopic stress at the same time. It is necessary, therefore, to evaluate the superimposed effect of macroscopic stresses the pitting damage. Pitting damage tests were carried out using a ultrasonic cavitation testing with a static tensile-stress loading unit. The results showed that the damage increased with the imposed tensile stress.

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There are numerous cases in which the outside surfaces of cylinders such as towers, piping and storage tanks are partially corroded under their insulation. The establishment of a FFS rule capable of judging these flaws has been awaited for a long time. In this paper, the plastic collapse condition of a cylinder with local thin area based on the reference stress is proposed. The method is verified by comparison with the experimental and FEA results.

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The High Pressure Institute of Japan has been updating Fitness-For-Service (FFS) rule (HPIS-Z101), which is a simplified assessment procedure for evaluating the structural integrity of cracked pressure vessels and piping systems. Now, Z101-Level 1 is being revised and more accurate assessment Level 2 including the evaluation of the leak before break (LBB) will be newly added. In this paper, the LBB procedure, which will be adopted in Z101-Level 2 is discussed. The method of estimating the crack profile when a crack penetrates the wall thickness is proposed.

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The transport behavior of a water molecule to a crack tip of SiO_2 is analyzed by using an atomistic simulation model. The crack growth velocity values are calculated based on the energy surfaces obtained by using this atomistic model. It is found that the calculated crack velocity values coincide well with the experimental values.

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An experimental crack detection method based on the changes in natural frequencies is developed. In the proposed method, the FFT is applied to the sensor signals picked up by a CCD laser displacement meter. Monitoring the changes of the natural frequencies and comparing the frequencies with those of sound (no-crack) specimen, we can detect the crack position and crack size. The proposed method is very simple in contrast with the other non-destructive detection method.

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In this paper, an analytical solution for an infinite strip having an eccentrically located circular hole is given when the strip is subjected to internal pressure around the hole. The solution is based on an approach involving Papcovich-Neuber displacement potentials and deduced using the simple forms of Cartesian and cylindrical harmonics. The boundary conditions on both sides of the strip and around the hole are completely satisfied with the aid of the relations between the Cartesian and cylindrical harmonics. The solution is shown in graphs and the effect of the eccentric hole on the stress distribution is clarified.

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