An exact approach for free vibration analysis of a beam with a crack and a concentrated mass is proposed. A model of massless rotational spring is adopted to describe the local flexibility induced by the crack in the beam. Using the Timoshenko beam theory on two separated beams respectively and applying the compatibility requirements at the crack position, the characteristic equation for this cracked beam with a mass can be obtained explicitly. Numerical examples are given to illustrate the proposed method and to study the effect of mass on the natural frequencies and mode shapes of the cracked beam.

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To reduce tensile residual stress in a welded region, a new cooling method-which rapidly applies a water-shower behind the welding-torch-was developed. In this study, the water-shower cooling was applied to a surface of multi pass bead on plates. To verify the effectiveness of the water-shower cooling on the tensile residual stress reduction on the welded surfaces of the multi pass bead on plates, residual stresses of the plates manufactured with or without water-shower cooling were experimentally determined. Experimental results show that tensile residual stress was generated on the welded surface when the water-shower cooling was not applied. The highest value of the tensile residual stress was more than 300 MPa. The experimental results also show that the tensile residual stress was improved to compressive when the water-shower cooling was applied. The highest value of the compressive residual stress was 200 MPa. It can be concluded that the water-shower cooling is effective for reducing tensile residual stress in the multi pass bead on plates.

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In this paper cross elasticity effects for general laminated composite plates are presented. The discrete governing equations under unconstrained conditions can not be solved because the stiffness matrix is singular. The modified equations is obtained from reducing the dynamic equilibrium equations under the constant velocity motion and the Rayleigh damping proportional to the mass matrix. The validity of computational method is confirmed by comparison of analytical results for the classical laminaton theory.

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In this study a new computational method of in-plane deformation analysis for plates are developed using frame element with two translational and a rotational displacements degree of freedom at each node. The method consists in replacing a three-node triangular element by three frame elements arranged along three sides of triangle. It's effectiveness is demonstrated through several beam problems.

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In this paper a new evaluation method of the effective elastic moduli for heterogeneous materials composed of isotropic constituent materials is presented. The effective elastic constants can be obtained to make two matrices numerically equal. One is the standard global stiffness matrix and the other is the stiffness matrix multiplied by an effective modulus, Young's modulus, shear and bulk modulus, Lame's constants. The result of Finite Element Analysis show good agreement with the analytical upper bound values by the Paul's method with an application of the principle of minimum potential energy.

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Infrared thermography detects thermal energy emitted from various objective surfaces, and it is a procedure for evaluating the surface temperatures nondestructively. We can diagnose and evaluate a two-dimensional temperature field having complicated shape every real-time pixel by using this technique, if an appropriate image processing technique is combined. The technique has therefore widely been used for various applications such as engineering, medical and industrial utilizations. In this paper the applicability of infrared sensing to nondestructive diagnosis for invisible mines installed in desert zones is experimentally and numerically investigated with the aid of an appropriate mathematical modeling.

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Closed-contact melting of solid phase change material (solid PCM) in a horizontal cylinder under constant heat transfer coefficient was investigated by an experiment and an analysis. Solid PCM of water and tetradecane filled in an acrylic and a copper tube was melted by natural and forced convection. Melting velocity measured by visualized solid liquid boundary increased with time under the constant heat transfer coefficient. This agrees with the analysis. Observation of the solid liquid boundary shows that for case of the melting in the copper cylinder, effect of natural convection in the liquid phase would be negligible, however, effect of natural convection can not be ignored for case of the melting in the acrylic cylinder.

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The controllability of external thermal insulation building with vent layer was investigated numerically and empirically. At first, the heat transfer and fluid flow of a fundamental flow system were analyzed to confirm the applicability of the present numerical computation. The visualization result by infrared thermography was compared with the numerical simulation, and in addition, the validity of the numerical simulation was also verified. The Optimum vent layer size, optimum thermal insulation thickness and optimum flow rate were considered along with developing the technique how to control the present thermal system by switching the vent.

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As one of the environment problem, heat island problem becomes serious owing to the concentration of population and industry in big cities around the world. Therefore, in this study, we focused on a heat shield paint which can reduce thermal storage in a concrete building under solar heating. The effect of the heat shield paint on the heat island problem was evaluated. Another aim is to clarify the thermal radiation characteristics of the heat shield paint.

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The multi-colored technique for quantitative temperature measurement is proposed by combining several kinds of infrared filters. The respective filters concerned have selective wavelength band several ,u m in width in the range of 2-13 L m. The applicability is confirmed using numerical simulation to allow a parametric study of how the result varies for different values of emissivity corresponding to the individual infrared filters. An experimental investigation is also performed to evaluate the measurement error and the adaptability of the technique. This method has a feature which allows quantitative temperature measurement for target surfaces at each picture element without presuming any emissivity, reflectively and ambient conditions, so that it may be useful across various medical or engineering disciplines.

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The biosensor that uses quartz vibrator to detect the environmental pollutant in the solution is researched. As for the phenomenon of adsorbing the surface of QCM and taking place the mass change, it is understood that the proportion works out between the amounts of the change on which the oscillation frequency of QCM falls. The research that detects the environmental pollutant is done by using this phenomenon. The QCM flow cell to use it in the solution so that the frequency change may clarify dependence on the inflw angle is produced, six kinds of sucrose solutions with different density are thrown into the flowfield of solution, and the experiment examination of the change in the number of QCM vibrations by the inflow angle dependency is done.

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Swirl flow occurs frequently in fluid machines and curved pipe line. The swirl flow in a circular tube may have higher axial velocity at the wall than the center due to non-uniform pressure in a cross-section of tube. It is interested in the swirl flow through an orifice plate because the distorted velocity profiles can affect the flow measurement and flow-accelerated corrosion of pipe wall. Using the laser doppler velocimeter, this study found the velocity distribution and turbulence intensity of swirl flow through the orifice plate, and the results appear to be physically reasonable.

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Low specific speed impellers are applied to high pressure ratio centrifugal compressors because of the small volume flow rate. Generally, the efficiency of the low specific speed impellers is lower than that of high specific speed impellers, because the small width of the flow passage makes the friction loss increase. Wedge impellers that have enlarged flow passage width by using the thick blades are developed for the purpose of efficiency improvement of the low specific speed impellers. The parameters of the functions that decide the blade angle and thickness are investigated. The suitable blade profiles are clarified by performance estimations for the various impeller profiles. Moreover, the designed Wedge impellers are manufactured and tested experimentally to evaluate its performances. As a result, the efficiency of the Wedge impellers increased by 4% and the operation range was greatly expanded compared with the conventional impellers that have thin blades.

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In late years, a typhoon and the flood damage by the heavy rain occur frequently, thereby importance of rainwater drainage pump facilities is extremely high. However, as for the existing pump facilities successive deterioration advances, therefore, by much maintenance technology, we maintain the reliability of pump. Therefore we developed the diagnosis technology that can check without dismantling A pump. We are using this technology now. In this announcement, I report about the contents and the application example about this technology.

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Cavitation damage, which is induced by pressure waves in mercury, is viewed as one of the critical issues to satisfy high power spallation neutron source. Microbubble injection into the mercury is under study to mitigate the pressure waves. The mitigation effect is dependent on bubble distribution and size. It is important to estimate its lifetime to determine the bubble distribution and injection position. However, data for the lifetime estimation in mercury are insufficient. In this study, helium microbubbles in contact with an acrylic wall were observed and their lifetimes were measured, since mercury is an opaque liquid. Based on the observed bubbles, actual lifetime of bubbles suspended in the liquid was estimated. It was found that lifetime of microbubbles in mercury is longer than in water.

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This study focused on the characteristics of water clarification by microscopic bubble. The two parameters which influence the particle size of bubbles, i.e. fluid flow and water temperatures, were investigated toward the depolution of water in hydrosphere environment. Measurements of bubble size were carried out with changing fluid flow at generator and water temperatures. After the generation of bubbles, the particle size and the number of bubbles were measured from 15 to 80 seconds. From the result, the effect of fluid flow on the particle size seemed to be small. On the other hand, at a constant flow, the higher the water temperature was, the smaller the particle sizes of bubble were. The size also became to be small in the course of time

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This study analyzed the characteristic of cycloidal propellers with 'Karman & Sears theory' and 'the vortex method', modeling the movement of the propeller as rotation with pitching and heaving movements. The reduced frequency which decides the characteristics of unsteadiness depends on the ratio of the length of the blade to the ration radius. In unsteady flow, thrust increased and its direction changed as the reduced frequency increased. Thrust efficiency calculated by the unsteady theory showed lower value than that obtained from the quasi-steady theory. Thrust efficiency in unsteady flow decreased sharply as the attack angle increased.

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In this study, electric energy generated by several large-scale commercial wind power systems was measured and the fluctuating quantities were investigated to consider the characteristic phenomena. Several physical fluctuating quantities: wind speed, wind direction in terms of the system were also analyzed to consider natural transient phenomena. The other aim of the present study is to establish the technique how to control the natural power plant: the optimum working condition.

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In late years, the application of the surface modification is paid attention as a means corresponding to achieve making of the material high performance and environmental harmony in each industry. Especially, application to the press metal mold industry is highest the share, especially, to improve lubricity and abrasion resistance, the coating of a hard film is given. However, when the press is continued tens of thousands of times, the damage of the goodness generates flaking off of the film in the starting point. This becomes a quality decrease of the product, in case of being longevity of the metal mold. Then, in this research, The improvement of the film adhesion was attempted by giving the middle processing to the metal mold mother material.

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In recent years, many energy saving or discharge curtailment of carbon dioxide are studied from the rise of the concern about global warming. Consequently, carbon dioxide was decrease by lightening of Automobile. Polymer materials ware chosen as a lightening material. In document investigation, it is possible to modified with DLC that was excellent at tribology characteristic to polymer materials. The friction wear-out examination of unprocessing plastics and plated plastics was done as previous step of DLC modification.

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In recent years, against the background of weight saving and downsizing in machines and devices, it is important subject to downscale mechanical parts which was combined in them. So in this study, in order to achieve power transmission parts like compact gearwheel which indicates high performance properties, hybrid surface modification which was combined SRIQ(Super Rapid Induction heating & Quenching) which creates high fatigue strength and DLC(Diamond Like Carbon) coating which are well known for their high hardness, low friction and excellent wear resistance was performed. And, in order to prevent the base material from decrease of fatigue strength, DLC was coated by using UBMS(Unbalanced Magnetron Sputtering) method which can coat at low temperature. Rotational bending fatigue tests and friction-wear tests were carried out. It was clear that it is possible to keep high fatigue strength and to create excellent tribological properties at specimen surface by performed hybrid surface modification. Furthermore, it is possible to prevent increase in handling process because tempering process after quenching can be performed by heat process during DLC coating process.

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In recent years, environmental problems including global warming made the Automobile Parts development toward Environmental Symbiosis Style. Therefore, Plastic Forming is trending grease reduction. However, with the harsh usage environment from spread the high tensile steel and grease reduction, Die life is shorter than before. As a result, Compound Surface Modification as technology solution has gotten a lot of attention recently. Then, the most important thing is design for Interface Adherence in Surface Modification. Therefore, selection and processing of materials play a key role in Surface Modification. In this research focuses on Material of Die, research about difference of Die life when the material of a different microstructure is used. The above-mentioned is shown below.

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In recent years, against the background of weight saving and downsizing in machines and devices, it is important subject to downscale mechanical parts which was contained in them. So in this study, in order to achieve power transmission parts like compact gearwheel which indicates high performance properties, hybrid surface modification which was combined SRIQ(Super Rapid Induction heating & Quenching) which creates high fatigue strength and DLC(Diamond Like Carbon) coating which are well known for their high hardness, low friction and excellent wear resistance was performed. And, in order to prevent the base material from decrease of fatigue strength, DLC was coated by using UBMS (Unbalanced Magnetron Sputtering) method which can coat at low temperature. Rolling-Sliding tests was carried out. It was clear that it is possible to create excellent fatigue strength by performed hybrid surface modification. The above -mentioned is shown below.

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A sliding parts is used for all equipment like information instruments, including the car industry and the office equipment, optics, and the medical treatment, etc. Then, this research did the compound surface modification to the pure iron so that the functionality of a sliding parts might improve. It eased and Namac did the Me-DLC coating of the hardness difference in the layer in five kinds of middle (Non-Electrolyte Ni Plating, Ion Nitriding, Radical Nitriding, super-NV Nitriding, Pionite Processing). The following things were performed in this research. A detailed experiment on the friction characteristics inclination of the next generation surface coating was done. Examine a basic friction abrasion mechanism in detail It is a necessary, indispensable for develop an excellent sliding parts in wear-out of the more friction basic knowledge.

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In recent years, It has been maked a positive approach about global environment problems in auto industry. As one of the countermeasures, weight saving is gone forward from iron and steel materials to light alloys. Magnesium alloy has been widely used because of its lightweight and ease recycling and so on. However, magnesium alloys are inferior in wear resistance. Therefore, it is necessary to improve this property to use magnesium alloy for more machine parts. So, in this study, DLC(Diamond Like Carbon) coating which are well known for their high hardness, low friction and excellent wear resistance was performed. In this case which DLC was coated on the soft material such as magnesium alloy, the adhesion strength between the substrate and the coating was important problem. So, in this study, in order to acquire the high adhesion strength, DLC coated process was performed by using UBMS(Unbalanced Magnetron Sputtering) method, and inter-layer which was doped Tungsten was formed on the substrate, and on the inter-layer two kinds of DLC coatings were laminated for nano order. Wear tests and fatigue tests were carried out. Magnesium alloy coated DLC indicated excellent wear friction. Furthermore, the fatigue reliability was elevated by DLC coatings compared with substrate only.

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Aluminum alloy has been used in several kinds of industries against a background of environmental problem and energy saving because aluminum alloy has a lot of advantages; lightness, recyclability and good corrosion resistance. However, aluminum alloy has poor wear-resistance, so in order to solve this problem, DLC (Diamond Like Carbon) coating which indicates high tribological properties was performed. However, there are some reports which are con-cerned that coated materials like DLC indicate low fatigue strength compared with substrate only due to high heating history during the coating process. So, in this study, in order to improve wear resistance and to (i) coating process was performed by using UBMS (Unbalanced Magnetron Sputtering) method, and (ii) inter-layer which was doped Tungsten was formed on the substrate, and on the inter-layer (iii) two kinds of DLC coatings were laminated for nano order. Wear tests and fatigue tests were carried out. Aluminum alloy coated DLC indicated very low wear rates, excellent tribological properties. Furthermore, it indicated high fatigue strength compared with substrate only.

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A developed grinding system employing super-fine abrasive wheels was used to fabricate ultra-fine micro-tools having a variety of shapes. The machine successfully produced a cylindrically shaped micro-tool having a tip diameter of less than I μm. The surfaces of the produced micro-tools were investigated by advanced analytical methods. Fracture strength of the micro-tools was evaluated by nano-indentation testing, and their surface chemical properties were analyzed by XPS. The results suggest that the surface of processed micro-tools might have been strengthened by allowing the penetration and diffusion of oxygen atoms into the material, and allowing oxidation.

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The use of a hard thin film is advanced by a recent automotive field. However, adhesion strength of a hard thin film is related directly at the product-life cycle. Adhesion was evaluated from the analysis of the destruction phenomenon on the interface between film with the machine of Nano-indentar hardness examination instrument. As a result, it was able to be confirmed that SEM in the film section was observed, and the destruction of the interface by the minimum pushing examination related to adhesion.

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Carbon-ion was implanted into tool steels by means of a plasma immersion ion-implantation technique. Various implantation conditions were used in order to investigate relation between mechanical properties and depth distribution of carbon in steel surface. The implanted surface was characterized by X-ray diffractmeter (XRD) for identification of in-situ synthesized carbide. Auger electron spectroscopy (AES) was used to determine the depth profile of the implanted species. Raman spectroscopy was utilized for the implanted surface. Substrate temperature was estimated from the hardness of tool steel substrate treated at simultaneously. Short term implantation with 20 kV of negative bias caused high concentration of carbon at the steel surface. After that, carbon film was deposited on the carbon enriched surface. Raman spectrum for the deposited carbon film showed that for a typical DLC film.

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In recent years, DLC(Diamond Like Carbon) coating, which is well known for its high hardness and excellent ware resistance, has been widely used in several kinds of industries. However, in general, it is not easy to control the friction coefficient of DLC coating. So, in order to apply DLC coating for more machines and equipments, it is important to clarify the method of controlling friction coefficient of DLC coating more easily. So, in this study, DLC coating was performed on the surface of substrate which was formed micro-dimples by using Fine Particle Bombardment(FPB). Three types of coated specimens with different surface roughness were prepared and wear tests were carried out. The coated specimens which was formed micro-dimples indicated stable friction coefficient for long distance significantly. Furthermore, it is possible to control the friction coefficient of DLC coating easily by changing the surface roughness of substrate; the rougher the surface roughness, the higher the friction coefficient.

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Although small molecule organic thin films have been applied to electronics, very few experimental results have been reported in respect to their mechanical properties. Here we report experimental results in which pentacene thin films were investigated for mechanical properties using the nanoindentation and the critical bending radius was evaluated using the properties on the basis of the conventional theory of slipline. The resulting values were well coincident with that from an experiment.

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In order to achieve high functionality materials which indicate high fatigue and high tribological properties, two surface modifications, high carbon carburizing and DLC(Diamond Like Carbon) coating, was performed to low carbon steel(SCM415). However, there are some reports which are concerned that coated materials like DLC indicate low fa-tigue strength compared with substrate only due to high heating history during the coating process. So, in this study, in order to prevent the base material from decrease of fatigue strength, DLC was coated by using UBMS(Unbalanced Mag-netron Sputtering) method which can coat at low temperature. Furthermore, three types of DLC coated specimens with different coating structures were prepared. Rotational bending fatigue tests and friction-wear tests were carried out. It was clear that the friction coefficient of each specimens coated DLC stabilized under 0.1. And, the specimen coated DLC with 5μm thickness indicates the highest tribological properties because the DLC coating was transcribed on the opponent material during wear process. Furthermore, the decreases of fatigue strength were not observed for each coated specimens. It can be concluded that it is possible to achieve high functionality materials by performed DLC hybrid sur-face modification suggested in this search.

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FPC (Flexible Printed Circuit) has been used extensively for wiring material of electronic because FPC has a lot of advantages; thin, light and enhanced flexibility. However, precise lifetime and destruction mechanism of FPC is not clear yet. So, in this study, in order to improve flexibility lifetime and to elucidation destruction mechanism, prepared specimen plated and non-plated S-side of electrolytic copper foil of FPC. Flexing test was carried out. Specimen plated S-side of electrolytic copper foil of FPC indicated high flexibility lifetime compared with specimen non-plated S-side of electrolytic copper foil of FPC.

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The press working is widely used from the height of mass production and the economy for the processing of the steel board for the car. Because the problem named wear-out, burning in the press working coming in contact by the high side pressure of the metal, the coating film to the surface of the metal mold has been introduced as measures. However, Widely used of high tension steel occurs problems film is damaged and film detachment by more load to shear their steels. So the mechanism of the damage was clarified in this research by the stress analysis that used digital engineering like CAD and CAE. In addition, try to make reduction of stress in damage points by changes of shape design.

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The derailments accident of railroad suffer a large number of casualties, and it occurred sometimes all over the world even now. Many causes of the derailment accident are that the wheel runs on a rail by high friction coefficient contact between the wheel flange and the rail. So, normally the lubricating oil is used in order to prevent the high coefficient contact. However, it has many problems to use the oil, for example oil maintenance cost and care for environmental problems. In this study, in order to achieve the low friction coefficient without using the lubricating oil, the surface modification treatment which indicates excellent tribological properties was suggested, especially DLC coating. Model wheels coated surface modifications were prepared. The friction and abrasion tests assumed actual condition were carried out. It is clear that to coat DLC only has no effect, so it is important to combine two or more surface modifications. By combining the surface modifications, it can be achieved low friction coefficient contact between the wheel flange and the rail without using the lubricating oil enough to prevent the derailments. Further more, in order to achieve more safety wheel, hybrid-MoS_2 coating was performed. This wheel indicated significantly low friction coefficient. It is possible to achieve security and safety wheel which can prevent the derailments by using hybrid-DLC and hybrid- MoS_2 coating.

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