From a viewpoint of global environment problems, we have to pay attention to reduce CO_2 from coal fired power. As you know, direct CO_2 capture has the problem that net power generation efficiency is decreased remarkably at present. For this reason, it is necessary to attach CO_2 capture technology to a high efficiency power generation system such as IGCC and IGFC. Through the demonstrations of IGCC, CO_2 Capture, and IGFC with CO_2 Capture, our policy is to develop. Zero-emission coal fired power station finally.

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CCS technology is expected to reduce CO_2 emission, but its net efficiency is supposed 29 to 33% (HHV) because capture unit requires large m-house power. Proposed "oxy-fuel IGCC system" can keep high thermal efficiency more than 40% even after capturing CO_2. This system gasifies coal with mixed gas of recycled CO_2 flue gas and necessary amount of O_2, just as oxy-fuel combustion. Therefore, CO_2 concentration in exhaust gas is so high that CO_2 capture unit is not required. Moreover, CO_2 gas accelerates coal gasification reaction as gasifying agent CRIEPI and Kyusyu university are running various programs to develop fundamental technologies for this system. This paper is to report the newest findings by CRIEPI. It was concerned with difficulties to design large-scale regenerative heat exchanger, one of key components of this system. But finally we succeeded to design compact large-scale regenerative heat exchanger.

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A CO-rich gasified coal fuel, derived from an oxygen-CO_2 blown gasifier, is burnt with oxygen under stoichiometric conditions in a closed cycle gas turbine for the highly-efficient, oxy-fuel IGCC (integrated coal gasification combined cycle) power generation system with CO_2 capture. Stoichiometric combustion is diluted with the recycled gas turbine exhaust and adjusted for given temperatures. In this study, we examined combustor emission characteristics and reaction characteristics of recirculating exhaust through numerical analysis based on reaction kinetics. Author had ever clarified that since CO oxidation was inhibited by CO_2 constituent in exhaust, combustion efficiency was estimated to be lower than those in the cases of the H_2/O_2 fired-closed gas turbines developed in the Japanese WE-NET project and the Pre-combustion IGCC. In this paper, I examined influence of O_2 concentration in oxidizer and equivalence ratio on the combustion characteristics. It was estimated that the increase in O_2 concentration resulted m a decrease in combustion efficiency, and that the decrease in equivalence ratio could not be enough to improve combustion efficiency.

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On the gas-turbine combined-cycle (GTCC) system, the thermal efficiency of by-product gas (pretreated blast-furnace gas) - fired GTCC is about 7 % lower than that of LNG-fired GTCC at combustion temperature of 1623 K. It is caused by the unnecessary contamination of CO_2 and N_2 So, the authors have developed the method for the efficiency improvement of by-product gas fired GTCC though the use of gas separation such as CO_2 and N_2^<(1)>. In this paper, in order to optimize the CO_2 gas separation method that is integrated with GTCC, the gas separation energy has compared with three different processes that are Amine process, Pressure Swing Adsorption (PSA) process and Membrane process. As a result, we found that the most effective gas separation system was. Amine process and it was important to consider and integrated the whole process.

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When CO_2 is injecting into marine sediments, CO_2 forms solid CO_2 hydrate and it blocks voids of the sediments. So an injecting method is necessary for long term injection in order to use CO_2. We have been focused into the exothermic heat of CO_2 hydrate. The heat can warm saturated sands by about 9 degrees centigrade. This means that the layers are warmed to phase equilibrium temperature between solid CO_2 hydrate and liquid We have shown CO_2 can flow at the phase equilibrium temperature CO_2/water emulsion can generate heat at the top of flow without blocking the voids. The emulsion flows through sands at the phase equilibrium temperature.

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Installation of the hydrogen vent equipment will be required for existing nuclear plants against severe accident. It is necessary to construct the analytical method to evaluate the performance of the hydrogen vent function. In this research, CFD was examined as an evaluation method of the hydrogen concentration in the reactor building. The condition that the gas of the hydrogen concentration 34% enters in the operation floor was assumed. It was confirmed that the temperature of the operation floor became uniform and the hydrogen concentration became less than 4% as a result of the analysis.

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An evaluation method to predict hydrogen density in BWR reactor buildings in case of severe accident is proposed. Lumped parameter system is adopted assuming the uniform distribution of hydrogen density. By the proposed method, we can obtain the evaluation result in a moment. The results agree well with the CFD calculations in both the steady state and the transient evaluation. Therefore we can substitute this method for CFD analysis, which needs a lot of computational time.

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Hydrogen venting in BWR reactor building (R/B) is an important issue in severe accident management. For this situation, an evaluation method to predict hydrogen density in R/B is proposed with lumped parameter system assuming uniform distribution in R/B space. Sensitivity analyses were conducted with this method to understand the effect of related parameter on hydrogen behavior and venting efficiency.

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The hydrogen vent is very important for existing nuclear plants against severe accidents Blow-out panel can be effective for the hydrogen vent. In this research, CFD was conducted to evaluate hydrogen behavior of the plant with flow-out panel. It was confirmed that the air outside of the building flowed into the building from the lower side of blow-out panel, which mixed with leaked hydrogen, and the mixed gas of air and hydrogen flowed outside of building from the upper side of flow-out panel.

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A study on flow-induced vibration in the primary cooling system of Japan Sodium cooled Fast Reactor (JSFR) has been conducted 111 Japan Atomic Energy Agency (JAEA). The flow-induced vibration in the elbow is an important issue in design study of JSFR consisting of large diameter pipe and elbow with short curvature radius, because it may affect to structural integrity of the pipe. In this study, Unsteady Reynolds Averaged Navier-Stokes equations (U-RANS) approach with the Reynolds Stress Model (RSM) using a commercial CFD code has been applied to the flow through single and double short-elbows under a high Reynolds number condition. This numerical simulation has utilized a 1/7 scaled water experiment of the JSFR cold-leg piping in order to investigate the flow structure in a three-dimensionally connected double elbow. As a result, applicability of the numerical simulation method was confirmed by comparison between the numerical and experimental results. The simulation has also shown that flow fields m the 1st elbow was different from that in the 2nd elbow and pressure fluctuation in the 2nd elbow was larger than that in the 1st elbow because their larger vortex flow structure.

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Research on irradiation embrittlement of heat affected zone, HAZ, in weldment of RPV was experimentally studied in JAEA. Test pieces simulated HAZ was used in the study, and the result showed no significant difference between the HAZ and base metal in microscopic and mechanical properties. This report shows the result of statistical analysis of HAZ ductile brittle transition temperature shift compared with that shown as an unified equation constructed from a database of surveillance test specimens.

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Earthquake and Tsunami proof of Japan Sodium-cooled Fast Reactor (JSFR) has been evaluated. As for seismic design, safety grade components are confirmed to maintain their functions even against recent strong earthquakes. As for Tsunami, in JSFR design, safety grade components are independent from component cooling water system. A gas turbine system with air cooling is adopted for emergency power supply, since JSFR does not basically require quick start-up of the emergency power supply thanks to the natural convection Decay Heat Removal System (DHRS). Even in case of long station blackout, the DHRS could be activated by emergency batteries or manually and be operated continuously by natural convection.

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In late 2001, due to rapid combustion of radiolysis gas, steam piping rupture accidents occurred in Japan and abroad BWR plant. In this study, to establish the structural integrity evaluation method for the steam piping in the case of rapid combustion of the radiolysis gas occurs, detonation experiments were conducted using various piping specimens that are assumed in the actual plant. Pressure data in the various piping were obtained for the validation of detonation analysis.

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Piping strength evaluation method on combustion of non-condensable gas (stoichiometric hydrogen/oxygen mixture) accumulated in the piping of boiling water reactor (BWR) has been developed. Detonation pressure of non-condensable gas was evaluated by the detonation calculation, then piping strength was calculated using the pressure obtained by the detonation calculation. In this paper, the calculation methods for evaluating the detonation pressure was developed, and the detonation pressure obtained by the calculation was validated using the results of the detonation experiments. It was confirmed that the detonation calculation agreed with the results of detonation experiments on the straight pipe, elbow, tee joint, and so on.

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Severe accidents of nuclear power plant include nuclear and thermal-hydraulic characteristics and the operation of safety systems for a long time. It is difficult to understand the evolution of plant-wide event from only numeric data by simulation. Visualization tool has been developed for the understanding of severe accidents. It displays in the animation , the damage or change in temperature, pressure, concentration, etc in the reactor vessel and containment, which was simulated by the severe accidents code, in order to be able to understand the basic effect and progress of the event.

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Measurement of void fraction and observation of bubble dynamics were carried out to investigate the mechanisms causing the net vapor generation (NVG) in subcooled upward flow boiling. The working fluid was distilled water and the heated surface of rather low contact angle was used in the present experiment Since no bubbles could stay at their nucleation sites even at the onset of nucleate boiling (ONB), departure of bubbles from the nucleation sites was not the cause of NVG in the present experimental setup. Following the departure from the nucleation sites, bubbles were lifted off the heated surface to be propelled into the subcooled bulk liquid at low pressures whilst they slid along the vertical heated surface at elevated pressures. As a result, the bubble life time at ONB was considerably shorter in the experiments conducted under low pressures. The distinct difference of bubble dynamics suggested that the mechanisms of NVG are dependent on the system pressure. At low pressures, some bubbles could be reattached to the surface after the lift-off at sufficiently low liquid subcooling Since the bubble life time was markedly elongated, the reattachment of bubbles to the vertical heated surface was considered to trigger the NVG. It was also found that the bubble reattachment usually took place following the coalescence of bubbles produced successively at the same nucleation site. The stochastic bubble motion induced by coalescence was hence considered to be a key phenomenon causing NVG. The NVG mechanism at high pressures is investigated in future studies.

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Heat transfer to the upper air flow from the lower hot water in a horizontal flow path is promoted by the influence of natural convection and evaporation. In the previous study, the correlation equation was obtained by experiment as the sum of the convective heat transfer and evaporation heat transfer. However, there is a question on the convective heat transfer, which was much larger than the calculated value. In this study, therefore, experiment was done using the flow channel made of acrylic resin with 100 mm height, 600 mm length and 50 mm width The heat transfer area on the bottom of the flow channel was 300 mm length and 50mm width. Air velocity in the flow channel was 0.164 〜 1.02 m/s and average temperature of the heat transfer surface was 313 and 353 K. Temperature distributions of air flow and the heat transfer surface were measured by thermocouples and a radiation thermometer, respectively. The measured heat transfer was compared with the value calculated by a correlation for forced convection and heat transfer enhancement due to natural convection was studied.

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A natural ventilation system is generally adopted for storage facilities of spent nuclear fuel. At the storage facilities of concrete casks built near the seashore, the air including the sea salt particles comes into the concrete casks and could cause SCC of the canisters made of stainless steel. In this study, we proposed a salt particle collection device with low pressure loss which does not interfere with the air flow into the building or the concrete casks. Pressure loss tests in a laboratory and salt particles collection tests in the field were performed. Performance of the device adapted for the concrete cask was evaluated using obtained data.

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The best-estimate code TRACE is validated with the stability database of SIRIUS-N Facility at low pressure. The SIRIUS-N facility simulates thermal-hydraulics of the economic simplified BWR (ESBWR) Numerical results exhibits flashing-induced density wave oscillation characteristics, since the oscillation period correlates well with single-phase liquid transit time through the chimney region regardless of the system pressure, inlet subcooling and heat flux Unlike Type-I and II density wave oscillations, the inlet or exit throttling does not affect stability boundary and oscillation amplitude of flashing-induced density wave oscillations significantly. Stability maps in reference to the subcooling and heat flux obtained from the TRACE code agrees with those of the experimental data at low subcooling region, though instability observed in the lower heat flux and higher subcooling region from the stability limit of the experiment.

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The boiling transition of BWR fuel occurs, when the liquid film flow becomes zero. To predict the boiling transition power, called critical power, the subchannel analysis method has been developed. However, that method depends on the empirical correlations, for instance, droplet deposition, droplet entrainment, flow regime and so on. This study focuses on the droplet deposition, especially, cross-section shape effect on the droplet deposition onto a channel wall. Usual droplet deposition rate correlations were developed based on the measurement data with simple flow channel, like a tube. However, actual cross-section shape of BWR channel is not round tube Moreover, it seems to be very difficult to perfume the droplet deposition measurement test with such an actual channel. Therefore, the cross-sectional geometry effect on the droplet deposition was investigated numerically. The numerical results showed the droplet deposition rate on the rod bundle was smaller than that on the round tube It means that we must consider the cross-section shape effect on the droplet deposition.

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In the 2011 Great East Japan Earthquake, serious damage occurred in power plants and industrial facilities. The Japan Society of Mechanical Engineers (JSME) has set up an investigation committee and investigated the seismic damage of mechanical equipment in these industrial facilities for the purpose of understanding the situation and causes of the damage in such facilities and improving of preparedness for the future earthquakes. From the questionnaire investigation and many site investigations, it is found that the damage of industrial facilities was mainly caused by one of the following causes or a combination of thereof "strong seismic motion", "soil deformation", and "tsunami". In the questionnaire investigation, many organizations mentioned that the means of communication and provisions for electrical outages/shortages should be improved in the future tasks. Although the earthquake caused a great deal of damage, seismic measures taken before the earthquake could mitigate damage of some facilities.

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The 2011 Great East Japan earthquake caused severe liquefaction in Tohoku and Kanto districts. About 27,000 timber houses, a lot of buried sewage pipes and roads were damaged due to liquefaction. In Tokyo Bay area, liquefaction occurred in a wide area from Shinkiba in Tokyo through Urayasu, Ichikawa and Narashino cities to Chiba City Dredged and filled soils must have been liquefied by the earthquake. The very long duration of the main shock and an aftershock 29 minutes later probably induced the severe liquefaction Sidewalks and alleys buckled at several sites, probably due to a kind of sloshing of liquefied ground Moreover, much sand boiled from the ground and the ground subsided significantly because the liquefied soils were very fine Many houses settled notably and tilted. Sewage pipes meandered or were broken, their joints were extruded from the ground, and many manholes were sheared horizontally. This remarkable damage might have occurred due to the sloshing of liquefied ground. In reclaimed land along Pacific Ocean, many facilities were damaged as well as Tokyo Bay area due to liquefaction. In an industry facility, oil fences tilted and machinery rooms sunk.

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In 11th March 2011, Great East Japan Earthquake that has Mw 9.0 attacked to East Japan, and it caused serious damage not only to human but also to industrial facilities and so on. In addition, lifelines, such as water, electric power and so on were broken and the quake-hit area was wide. Therefore the disaster had a harmful influence on the Japanese industry. In order to investigate factors of the seismic damage of mechanical structure and improve preparedness for the future earthquakes,. The Japan Society of Mechanical Engineers (JSME) has set up an investigation committee. This paper describes the seismic damages of industrial facilities by the 2011 Great East Japan Earthquake. The features of the disaster were wide quake-hit area and after quake. The quake-hit area was so wide, thus supply chains damaged as well Large damage was caused by after quakes from small failure that was suffered by the main quake.

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In 11th March 2011, Great East Japan Earthquake that has Mw 9.0 attacked to East Japan, and it caused serious damage not only to human but also to industrial facilities and so on. In addition, lifelines, such as water, electric power and so on were broken and the quake-hit area was wide. Therefore the disaster had a harmful influence on the Japanese industry. In order to investigate factors of the seismic damage of mechanical structure and improve preparedness for the future earthquakes, The Japan Society of Mechanical Engineers (JSME) has set up an investigation committee. This paper describes the seismic damages of industrial facilities by the 2011 Great East Japan Earthquake. The damage by the disaster was serious. On the other hand, some good practice to prevent seismic damage was reported For example, vibration control damper of a building operated effectively. Employees of companies dealt with problems by the disaster effectively, in consequence of training for accident.

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This report deals with the seismic damages of cranes. A lot of industrial facilities suffered from the Great East Japan Earthquake on March 11, 2011. As the damage of cranes, it is classified roughly in the damage by earthquake vibration and the damage by a tsunami. In the case of earthquake vibration, many overhead travelling cranes were damaged Especially, elongation and break of the volts which suppressed a run rail to support occurred. In addition, the damage was seen in the run rail base structure of container crane. Furthermore, the wheel of the overhead travelling cranes and the gantry cranes came off its axle. In the case of tsunami, the damage of unloaders and container cranes happened The great east Japan earthquake investigation/proposal subcommittee stated in JSME, and investigation of the damage situation has been carried out. In addition, Japan Crane Association investigated the damage of cranes, and the situation has been clarified. In this report, the damage patterns, problems of cranes and improvement points are shown based on knowledge that was provided from damage investigation.

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The devastating earthquake of Mw9.0 hit the Tohoku district, north-east part of Japan on March 11, 2011. About 16,000 people died and 3,000 people were missing by the strong motion and tsunami, and the economic damage was estimated about 16.9 trillion yen except for the influence by the nuclear accident of Fukushima Danchi Nuclear Power Plant. The industrial facilities, power plants, or research facilities were damaged in this earthquake, and various kinds of mechanical equipment set in these facilities were also damaged. The Thermal and Nuclear Power Engineering Society had set up the investigation committee and investigated the seismic damage of mechanical equipment of these industrial facilities for the purpose to understand the situation and cause of the damages in such facilities and contribute to improvement of preparedness for the forthcoming earthquake. The main damages of thermal power plants due to the Great East Japan Earthquake on March 11,2011 were caused by surging giant tsunami after the main shock, rather than earthquake vibration. The tsunami washed out vehicles, tanks and utility-facilities, which were placed in the power plants Machinery equipment installed on the lower floor of turbine building and lower part of boiler was respectively fatally damaged, and electric facilities such as panel boards and motors caused insulation fault by being emerged in sea water. There were no significant damages for facilities due to liquefactions in case of that foundation piles and ground improvement had already been earned out. Electric power facilities themselves don't have major problems regarding earthquake-resistance strength, but the design considering tsunami should be established in near future.

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The devastating earthquake of Mw9.0 hit the Tohoku district, north-east part of Japan on March 11, 2011. About 16,000 people died and 3,000 people were missing by the strong motion and tsunami, and the economic damage was estimated about 16.9 trillion yen except for the influence by the nuclear accident of Fukushima Danchi Nuclear Power Plant. The industrial facilities, power plants, or research facilities were damaged in this earthquake, and various kinds of mechanical equipment set in these facilities were also damaged. The Thermal and Nuclear Power Engineering Society had set up the investigation committee and investigated the seismic damage of mechanical equipment of these industrial facilities for the purpose to understand the situation and cause of the damages in such facilities and contribute to improvement of preparedness for the forthcoming earthquake. The main damages of thermal power plants due to the Great East Japan Earthquake on March 11, 2011 were caused by surging giant tsunami after the mam shock, rather than earthquake vibration The tsunami washed out vehicles, tanks and utility-facilities, which were placed in the power plants. Machinery equipment installed on the lower floor of turbine building and lower part of boiler was respectively fatally damaged, and electric facilities such as panel boards and motors caused insulation fault by being emerged in sea water. There were no significant damages for facilities due to liquefactions in case of that foundation piles and ground improvement had already been earned out. Electric power facilities themselves don't have major problems regarding earthquake-resistance strength, but the design considering tsunami should be established in near future

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The devastating earthquake of Mw9.0 hit the Tohoku district, north-east part of Japan on March 11, 2011. About 16,000 people died and 3,000 people were missing by the strong motion and tsunami, and the economic damage was estimated about 16.9 trillion yen except for the influence by the nuclear accident of Fukushima Danchi Nuclear Power Plant. The industrial facilities, power plants, or research facilities were damaged in this earthquake, and various kinds of mechanical equipment set in these facilities were also damaged. The Japan Society of Mechanical Engineers (JSME) have set up the investigation committee and investigated the seismic damage of mechanical equipment of these industrial facilities for the purpose to understand the situation and cause of the damages in such facilities and contribute to improvement of preparedness for the forthcoming earthquake. This paper provides a summary of the typical damages of a semiconductor manufacturing factory. This facility had been promoting various measures such as not only seismic reinforcement of the facilities but also one of the earliest introduction of the Early Earthquake Warning system. Thereby, although the facility was hit by unexpected massive earthquake, the structural damage was considered to be kept to a minimum.

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The devastating earthquake of Mw9.0 hit the Tohoku district, north-east part of Japan on March 11, 2011. About 16,000 people died and 3,000 people were missing by the strong motion and tsunami, and the economic damage was estimated about 16.9 trillion yen except for the influence by the nuclear accident of Fukushima Danchi Nuclear Power Plant. The industrial facilities, power plants, or research facilities were damaged in this earthquake, and various kinds of mechanical equipment set in these facilities were also damaged. The Japan Society of Mechanical Engineers (JSME) have set up the investigation committee and investigated the seismic damage of mechanical equipment of these industrial facilities for the purpose to understand the situation and cause of the damages in such facilities and contribute to improvement of preparedness for the forthcoming earthquake. This paper provides a summary of the typical damages of a semiconductor manufacturing factory. This facility had been promoting various measures such as not only seismic reinforcement of the facilities but also one of the earliest introduction of the Early Earthquake Warning system. Thereby, although the facility was hit by unexpected massive earthquake, the structural damage was considered to be kept to a minimum.

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The devastating earthquake of Mw9.0 hit the Tohoku district, north-east part of Japan on March 11, 2011. About 16,000 people died and 3,000 people were missing by the strong motion and tsunami, and the economic damage was estimated about 16.9 trillion yen except for the influence by the nuclear accident of Fukushima Danchi Nuclear Power Plant. In addition to the main shock, many strong aftershocks occurred in the long term until June in 2011. The industrial facilities, power plants, or research facilities were damaged in these earthquakes, and various kinds of mechanical equipment set in these facilities were also damaged. The Japan Society of Mechanical Engineers (JSME) have set up the investigation committee and investigated the seismic damage of mechanical equipment of these industrial facilities for the purpose to understand the situation and cause of the damages in such facilities and contribute to improvement of preparedness for the forthcoming earthquake. This paper provides a summary of the investigation, mainly carried out by the Japan Elevator Association^(1), in order to contribute to improve the seismic design of the elevator systems for forthcoming destructive earthquakes. Typical damages of elevator systems and escalator systems utilized in buildings are also shown in this paper. Although the many of the buildings were hit by unexpected massive earthquake, the system damages were considered to be reduced to a certain level especially for the systems designed after the newly issued 2009 Seismic Design Guideline^(2).

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The great earthquake and tsunami hit the Tohoku, Central and north of Japan on March 11, 2011. Also many strong aftershocks occurred in the long term until June in 2011. The earthquake including aftershocks and tsunami awfully damaged the buildings and building facilities This paper provides a summary of the typical damages of elevators' and escalators' equipments and of the building walls concerned with elevators and escalators according to the investigation^<(2)(3)> by the Japan Elevator Association, in order to contribute to improve the earthquake-resistant design for the forthcoming earthquake.

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In this paper, a number of artificial earthquake ground motions compatible with non-stationary time-frequency characteristics as well as the given target response spectrum are generated using wavelet transform. The maximum displacement, velocity and acceleration responses of elasto-plastic structures by excited these artificial earthquake ground motions are calculated numerically. Displacement response, velocity response and cumulative input energy are shown in the case of the ground motion which cause larger displacement response. Under the given design response spectrum, a selection manner of generated artificial earthquake ground motion which causes larger maximum displacement response of elasto-plastic structure are suggested.

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We investigate running stability of the high-speed-moving vehicle subjected to the various seismic excitation. The analytical model of the vehicle consists of one body, two trucks and four wheelsets, and has a total of 21 degree of freedom. Some springs of vehicles called stoppers are modeled as a nonlinear spring in order to reduce relative displacements. The equations of motion are derived from the Lagrange equation We use the possibility of the rollover of the vehicle in order to evaluate running stability of the high-speed-moving vehicle as evaluation index. The vehicle is excited by inputting the various seismic waves of EW and UD directions simultaneously. We focus on the effect of the maximum acceleration and predominant period. The maximum acceleration and predominant period of the seismic input are modified. The response behaviors of the vehicle on the straight and the curve rail track are simulated with the modified seismic input.

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Vibration modes measurement and an analysis method on the partially stiffened cylindrical shell with attached mass which contains liquid partially in it, were developed. Since it was measured that the harmonic numbers of circumferential vibration modes of the liquid filled lower part is different from that of the empty upper one, a finite strip method, which is taken into account the geometrical stiffness of hoop stress due to the contained liquid, partial mass and stiffness by attached elements, was developed. As a result, experimental natural frequencies that the harmonic numbers changes along axis are good agreement to those by analysis.

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We propose energy- harvesting device using an iron- gallium alloy (Fe-Ga), which is capable of generating electrical energy from ambient vibrations. The device consists of parallel beams structure of yoke and Fe-Ga plate wound with coils, and a bias magnet. A bending force applied at the tip of the device yields a flux change of Fe-Ga plate, which the time variations generates a voltage on the wound coils. In this paper, power generation characteristic of high frequency mode is investigated. The experimental results and modal analysis clarified that high power generation is possible if the uniform bending deformation is occurred in the parallel beam structure in high frequency resonance.

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This paper deals a seismic isolation system with nonlinear characteristics mechanism for a vertical seismic oscillation. The seismic isolation system consists of a rhombus shape link, horizontal coil springs and vertical coil springs. Restoring force of the system can be calculated by the geometric calculation. The authors propose a design principle of the system, using that natural period of the seismic isolation system can be calculated from its restoring force characteristics. A Seismic isolator using the nonlinear characteristics was actually made, and its restoring force characteristics were measured by static loading test From this experiment results, it revealed that the characteristics of the device can be accurately predicted from the design principle.

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For suppressing the sliding motion of the cask, the authors developed a sliding motion suppression system utilizing high viscous fluid and coaxial circular cylinders. Coaxial circular cylinders are installed at the bottom end of the cylinder and high viscous fluid is installed in the annular spaces. High viscous fluid in the annular spaces will cause very large added damping effects, thus sliding motion will be expected to be suppressed. In this study, added damping effects of the annular space fluid and sliding motion suppression effects are studied analytically and experimentally using a fundamental test model. It is found that increase in fluid viscosity brings us very large displacement suppression effects, however, at the same time, response acceleration increase which should be reduced in the view point of mitigation of rocking motion and structural integrity of the inner structure. Therefore, it is said that optimization in fluid viscosity will needed.

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This paper deals with two dimensional base-isolating device for sick person's bed in ambulance. This device does the reduction response acceleration by using pendulum type inclination chassis on horizontal direction. And, this device does the reduction of relative displacement and response acceleration by using restorative force from compression spring and friction force on vertical direction too. The performance check of a base-isolating device is shown from experiment in a base-isolating device by an ambulance and Conduct simulation analysis and the experiment using vibration exciter using the experimental result by an ambulance.

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In this paper, a new vibration control device called pendulum-type tuned mass damper (P.T.M.D) is proposed to reduce an ordinal house vibration. In recent years, three or four stories houses are built increasingly in the urban areas to obtain wide living space. These houses are subjected to a problem caused by the traffic vibration, because a dominant frequency of the traffic vibration is coincident with the natural frequency of these houses. Although tuned mass dampers (T.M.D) are considered to solve the problem, it needs to prepare a large mass on the top floor of these houses in order to obtain effective vibration reduction. On the contrary, P.T.M.D can be placed between the first and second floor and it acts effectively on the principle of lever mechanism, since an action of the mass is expanded. A semi-optimal design approach for the P.T.M.D is described, while it has an adjustable mechanism for adapting various specifications of these houses. Effectiveness of a P.T.M.D made by a full-scale is demonstrated theoretically and experimentally by controlled results using frequency, time and seismic responses. Also this paper shows that the P.T.M.D is effective against random vibration like earthquakes.

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The spent fuels from nuclear power stations are stored in a cask until reprocessed. It is concerned that the cask turns over when an earthquake occurs, because it is generally freely standing on a horizontal floor. This study investigates the rocking motion of a cask experimentally and analitically using CAE software named MATLAB which can simulate the rocking motion. When earthquake occurs, rocking and sliding motion will occur at the same time, however we consider the motions separately. A cask is huge and the weight is about 157t, therefore we make a reduced scale model. The scale factor is 1/1000 and the weight is about 15kg In the experiment, we excite the experimental model by applying initial angle or sinusoidal wave, and rocking angle is measured. The experimental results are compared with the Analytical ones to check the validity of the analytical method. In the analysis, we vary the coefficient restitution, and study the validity of the analytical model on restitution coefficient Next, we suggest Gyro system in order to prevent the rocking motion This Gyro system gives the cask Gyroscopic effect, thus the rocking motion can be reduced In the analysis, it is found that the rocking motion can be suppressed.

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Generally, mechanical structures are required to be highly safe to withstand a lot of earthquakes. Therefore, seismic evaluation and design techniques that are able to evaluate cumulative damages have been required. According to studies on failure of pipes, the load due to earthquake is a cyclic loading. The relationship between failure and the energy is evaluated, examined by paying attention to the Energy Balance Method said to be effective as an earthquake response analysis technique in the present Moreover the Energy Balance Method has aimed at the generalization of the earthquake-proof evaluation technique. This study carries out failure experiments using simple single degree of freedom models having various cross sections. Although the object dealt with by this research until now is a simple single degree of freedom model of hundreds of gram order, in order to perform detailed earthquake-proof evaluation for an actual mechanical structures, examination by the large mass type model near a real structure is needed. The consideration of the influence of the section modulus or the moment of inertia area on the energy required to failure is examined as a parameter of the shape of cross section by using the model of tens of kg order, by focusing on the microscopic response for the strain of point of failure.

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On March 11th, 2011, the Pacific coast of Tohoku Earthquake caused damages to Industrial facilities with a seismically isolated structure. For that reason, in order to improve the safety evaluation methods on the current isolation systems, a new estimation using higher earthquake standards inputs are required. This paper deals with the earthquake response analysis of the seismic isolation equipment for nuclear power plants using laminated rubber bearings. The high amplitude of this new input shows a hardening property of the rubber bearing in the horizontal direction and a softening property in the vertical direction So far, the horizontal and vertical directions analyses are considered independently, but in reality, there is a mutual influence between the horizontal and vertical behavior Consequently, in this paper, the analysis of the coupling between those two directions will be earned out. Then, after comparing these two approaches, the utility of considering this dependency will be estimated.

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In recent years, because of demand for rebuilt the building that were constructed in high economic growth period (1960s), demolition work is carried out energetically in many places in Japan Heavy equipment such as excavators is commonly used to the demolition work. However, the excavators generate uncomfortable vibration to neighbors. Therefore, the purpose of this study is research and development of vibration control device for excavators. A Tuned Mass Damper (TMD) is most commonly used for vibration control. Usually the TMD is tuned by using optimal design formula for the weight and the stiffness of the control target However the tuning violated if the parameters of the control target are changes. In order to solve this problem, a Multiple Tuned Mass Damper (MTMD) is proposed in this study. The MTMD consists of a primary mass and secondary mass. The secondary mass is placed on the primary mass in series. Applying the secondary mass can widen the effective target frequency range of vibration control. In this paper, prototype MTMD was fabricated and its performance was verified experimentally. As a result, the prototype MTMD provide superior performance, except in some cases.

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In the operation of industrial plant, it is essential that we ensure the piping integrity and safety. A serious problem of pipe is wall thinning because of erosion and corrosion (mechanical process and chemical process) Sometimes, the damage brings about the wholesale destruction of pipes, which will harm human on a large scale. In general, the wall thickness of pipe is measured with the ultrasonic test now However, we expend much time and effort on the test and there are damages, which aren't measured by the test. In this study, we pay attention the pipe's surface vibration by fluid vibration of tube, and suggest that the measurement vibration analysis for piping integrity. If method of this study is available, it is expected that we will make an examination of pipe in operation of plant, grasp the condition of extensive pipe, and reduce the time of test. This paper has research findings of fundamental study for new method measuring wall thinning (transition of frequency distribution and frequency response). The analysis method is Fast Fourier Transform and Transfer Function by MATLAB.

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Various vibrations adversely affect human body or structures. Therefore, vibration measures have been investigated by many researchers for many years. Especially, a seismic isolation is attracting attention owing to recent huge earthquake. Among devices of the isolation system used in large structures such as buildings, a friction damper that generates a large damping force is simple. ln mechanism and. It is easy to maintain. However, the ordinary friction damper of constant frictional force has performance limitation, because the isolation characteristic declines when the friction force is large, while resonant peak becomes large when the friction force is small Furthermore, the displacement remains apart from the equilibrium position after the disturbance disappeared. It is known that these problems are avoided when the friction force varies depending on the relative displacement Recently, Yamaguchi et al proposed the damper that the friction force varies in proportion to relative displacement by combining the tilt lever supported with pivot and the cylindrical block. In this paper, we propose more simple mechanism consisted of the tilt lever supported with the leaf spring and the cylindrical block When the cylindrical block moves and pushes the tilt lever, the normal and friction forces at the contact surface vary according to the displacement of the cylindrical block.

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To evaluate rolling friction coefficient, 4 wheels (discs) type test were conducted. Measured data of rolling friction were compared with the estimated data based on the elastic deformation profile of the Hertzian contact profile.(1) The static rolling friction coefficient can be estimated by the method of moment balance of contact width and the radius of a wheel at the contact end Estimation error of friction coefficient is less than 0.01.(2) The dynamic rolling friction coefficient can be estimated by the work balance of the lift (depth of elastic deformation) and the shift of wheel center. Estimation error of friction coefficient is less than 0.001.

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The power losses of a spur gear drive change with the gear rotation speed When a gear rotates at a high speed, churning loss is the main power loss. In this study, we investigated the effects of the driving conditions on the churning loss of gear drive. In the experiment, only one gear was rotated to measure only churning loss of the gear in oil bath lubrication. The experiments were carried out with spur gears of several modules and circular disks of several diameters in several types of lubricant oils. Then, we investigated the relationships among the churning loss with the depth of teeth, the diameter, the viscosity, and the gear speed. As a result of this study, only the oil viscosity has an influence on churning loss regardless of oil type when only one gear rotates High gear speed provides large churning torque Large module of the gear causes large churning torque. The gear has higher churning loss than circular disk without tooth.

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The purpose of this paper is developing the simulation of loss torque of gears based on the frictional loss generated by meshing. The frictional loss of gears is generated by the shear force of the oil film. Therefore the frictional loss was calculated by applying the visco-elastic-plastic model. The load distribution of the teeth was calculated by using FEM. The experimental value of the frictional loss of gears was measured by using the power circulating type gear test machine. The bearing loss, and the churning loss, wind loss and seal loss were also measured in order to separate them and frictional loss from the total losses. The tendency of calculation, that frictional loss became lower if rotational speed increases, agreed with experimental result. However, the calculated frictional loss became higher than the experimental result. It is necessary to consider the influence of vibration for improvement of accuracy of simulation.

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We had already analyzed the mechanical loss factor of the geared motor, which is composed of a motor of rated power 90W and a parallel gear reducer with total reduction ratio 9 and 18 Gear mesh was lubricated with the grease of NLGI consistency class 2. The high factor of loss was grease at no loading, and the friction of tooth flank at loading. In this paper, we presumed the mean friction of coefficient of tooth from the friction loss torque of tooth flank by experimental analysis and Niemann's formula. The result shows that mean friction of coefficient of tooth was a steady value of 0.12, which is independent of load torque and rotational speed.

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In order to reduce windage loss in a gear box, this paper presents a method to realize low air pressure in the gear box. The gear pair is operated like a gear pump with a tip cylinder fixed at mesh approaching region. The paper focuses on temperatures of the air in the gearbox and equipment components to find out sources of heat generation in the test rig. Air adiabatic compression between gear teeth is noticed to be the mam cause of heat generation. Then, we designed a pocket at the side block to release the air between mating gear teeth. As a result, all equipment components show an obvious drop in temperature.

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