In the previous paper, a collision vibration in continuous system excited by periodic displacement with arbitrary function was analyzed by the authors. A system of the steady state forced vibration in a cantilever beam having an attached mass at free-end was considered. The cantilever beam had structural damping in the beam, and it was being put in a viscous fluid with hydrodynamic drag. The attached mass collided elastically with the coil spring clamped on asymmetrical faces. In order to analyze an exact solution of the resulting vibration, the Fourier series method was applied to the system. And some resonance curves were constructed by numerical calculation. This paper deals with the method of stability analysis for the resulting vibration obtained in the previous paper. Stability criterion for the periodic solutions is analyzed utilizing variational equation of motion given from modal equation. Next, the stability charts for the resulting vibrations are constructed by numerical calculation. By using these charts, the stable branches for the resonance curves obtained in the previous paper are distinguished from the unstable ones. Furthermore, in order to clarify the influence of structural and external damping for the stability, the stability chart is also constructed taking the structural and external damping as parameter.

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This study deals with coefficient of restitution of camera mirror models. Coefficient of restitution differs depending on collision position. Because mirror models are made of thin sheet metal, it is expected that the vibration mode of it influences the coefficient of restitution. The objective of this study is to find the position of collision on the model with the minimum coefficient of restitution, and to find the relationship between the vibration mode of the model and the coefficient of restitution. As a result, the position of minimum coefficient of restitution is able to forecast by theoretical modal analysis. The next problem is to forecast the tendency of coefficient of restitution.

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We discuss the relationship between the damping characteristics and arrangement and motion of granular materials. Experimental investigation into the dynamic behavior of vibration system with granular materials has been carried out using forced vibration system with single degree of freedom. Firstly we evaluated the characteristics of vibration system with granular materials when the contact-angle of cylinders were changed. Secondly, we used square columns as granular materials and in this case the maximum damping effect was obtained.

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The method of collision analysis between granular materials and a plate is investigated numerically and experimentally. The motions of granular materials and the plate are analyzed by using the discrete element method and the finite element method, respectively. The damping characteristics of the plate are given by the Rayleigh damping. The validity of the analysis method is examined by a comparison of the experimental results. In the experimental approach, the response of an aluminum thin plate was measured when some steel balls collided with it. The contact behavior of the plate is evaluated by the displacement response and the frequency response of the plate.

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In this paper, a numerical modeling method for particle damping is presented. The numerical modeling is executed by using analytical results for the motion of the granular materials in the damper cavity under sinusoidal excitation. The damping effect for particle damping is modeled as equivalent additional mass, nonlinear spring force and viscous damping force by means of the discrete element method. The validity of the method is examined by a comparison of the experimental results. Analytical solutions are provided to estimate the response of the primary system under sinusoidal excitation.

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"Particle damper" is well known as a technique for add damping to a vibrating structure by filling it with many particles. One of the biggest advantages of this technique is that a damping effect can be achieved over a broad frequency range by the damper. Moreover, the damping effect is not dependent on temperature unlike many visco-elastic damping materials. However, it is also well known that the effect depends on a vibration amplitude. If a direction of vibration is vertical, and the acceleration of vibration is less than 1G, the particle damper has little damping effect. The purpose of this report is to propose a new damper which gives a high damping effect even though the acceleration is less than 1G. The bottom of the proposed damper is made of a leaf spring and it accelerate the vibration acceleration of particles to generate the damping effect. Results of a experiment proved that the proposed damper gives a high damping effect even though the acceleration of vibration is less than 1G.

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Colloidal damper is a new damper which uses a principle of difference of surface extension force, which is occurred by the direction of movement of surface. Some characteristics of the colloidal damper were investigated by our group. That is, a damping characteristics of colloidal damper for the amount ratio of silica gel and water, volume of cylinder and pre-pressure of the cylinder by changing exciting frequency and displacement of a piston. By using these results, this paper presents a design method of the colloidal damper, that is, diameter and length of a cylinder, pre-pressure in the cylinder, ratio of silica-gel and water. In order to show a flow of this design method, suspension of car which is composed by colloidal damper and spring, is presented.

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Colloidal dampers are able to dissipate large amounts of mechanical energy without significant heating, and such result is surprising since traditional hydro-pneumatic absorbers transform almost integrally the dissipated energy into heat. Trying to get deeper insight into this phenomenon, in this experimental work, using a thermographical method the temperature distributions on the external surface of a colloidal damper are recorded during its forced heating followed by its natural cooling. Employed compression-decompression cylinder is axially divided into two chambers, one of constant volume and the other of variable volume. Silica particles are introduced inside the cavity of fixed volume (silica tank), and a micro-filter is used to separate it by the chamber of variable volume, in which only water is supplied. Two main heat sources are identified as the silica tank (colloidal effect) and the packing used to seal the cylinder (frictional effect). Tests prove that heating/cooling through colloidal effect is much slower than heating/cooling through frictional effect. However, depending on the working frequency, generated heat power through colloidal effect can exceed the generated heat power through frictional effect. Based on the slow speed of heating/cooling through colloidal effect experimentally observed, one suggests that silica tank can be regarded from a thermal standpoint as a thermostat.

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The authors develop a circular arc shaped spring damper in order to keep soundness and reduce damage wooden structure when the earthquake is happened. The spring damper is composed of viscoelastic material which is sandwiched by two steel plates. It is able to strengthen stiffness by the steel plates, and give a damping by viscoelastic material. The damper is available for not only wood houses, also old structures such as castles and temples, since it can be attached easily. In this paper to investigate basic properties of the viscoelastic material, adhesive strength after thermal shock tests and heating tests, and force-displacement curves are measured by using a tensile testing machine. Next, to confirm performance of the damper, force-displacement curves in several cases of frequency or heat dependence, and durability are measured by using a shanking actuator. Addition to the above tests, the tensile strength of the coach screw bolt which is used for attachment to the column and the beam is also measured for practical use. Finally, validity of the material is confirmed from these experiments.

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The damping force of the magnetic damper in this paper is based on Lorentz force by Fleming's left-hand rule. That is to say, the force acts on the conductor in the opposite direction of the movement of the conducting disk. Generally, a magnetic damper has a weak point that damping performance is relatively weak. In the present work, we propose Halbach magnet array or another magnet array system to apply to the higher performance magnetic damper. In the case of Halbach magnet array, the five cubic magnets are glued in the different special direction of the magnetic pole each other. We fabricated the magnetic damper using one Halbach magnet array made of 5 ferrite magnet cubes and calculated damping ratios experimentally, and compared them with analytical results. As a result, it was found that we need to use plural Halbach magnet array or special magnet array made of neodymium magnets in order to gain the higher damping ratios.

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The fixed points theory is applied for the dynamic absorber attached to two degree of freedom system which consists of two identical single degree of freedom systems connected in series. The frequencies of fixed points and the ratio of natural frequencies to equalize the amplitudes at fixed points are analytically derived, in case that the responses at fixed points are in phase. The damping coefficients which make fixed points extremal value are also obtained. The geometric mean of the damping coefficients is suitable. Comparison of the analytical solution and numerically computed results whose responses at fixed points of equal amplitudes are π rad out of phase, shows that these dynamic absorbers have almost same performance of vibration suppression.

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We pay attention to the fact that free vibration amplitude of rigid body decrease rapidly without dampers or damping materials. We consider rocking of rigid body is very attractive as a low cost dynamic vibration absorber. In the previous paper we propose new type rigid bodies which base shape are not flat in order to design damping characteristics of rocking of rigid body in wide range without fall. However, natural frequency of the rocking of the rigid bodies has strong amplitude dependency. In this paper, in order to apply rocking of rigid body to dynamic vibration absorber, amplitude dependency of natural frequency of rocking rigid body is examined, and approximate equations to calculate natural frequency and damping ratio of several types of rigid bodies are derived to discuss how to improve amplitude dependency of natural frequency. Effects of the base shape on amplitude dependency of natural frequency and damping ratio are discussed using the derived equations. From the discussion it can be seen that rigid bodies which vase shape is near circular arc can improve amplitude dependency of natural frequency.

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This report presents a simple method to reduce flexural vibrations in a railway vehicle carbody just by supporting underfloor equipments using high-damping elastic mounts. Recent studies by the authors show that on-boarding passengers have large additional damping effect on the carbody flexural vibrations. Since a human as a elastic body itself has relatively large damping coefficient, we tried to simulate the additional damping effect of passengers by supporting underfloor equipments using high-damping elastic material. Some numerical studies are firstly carried out to check the feasibity of the idea using simple single degree of freedom and two degrees of freedom systems. Then, two types of elastic mounting devices are built for actual railway vehicle. A series of excitation tests are conducted in the rolling stock testing plant in the Railway Technical Research Institute (RTRI) using a commuter type test vehicle by applying those elastic mounting devices, and good vibration reduction performances are observred by the tests.

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In this study we investigate cylindrical dynamic damper to reduce electro-magnetic vibration of electric rotating machinery as turbine generator. In a turbine generator, the rotating electro-magnetic pull force of the rotor causes the stator core vibration of the oval deformation rotating synchronously with the rotation speed of the rotor. Applying a cylindrical dynamic damper to the stator core, one of the responses of the oval natural modes can be reduced, and we get the stationary deformation shape on the stator core for the electro-magnetic force. Then the transmission of the electro-magnetic vibration to the base of the generator from the stator core can be efficiently reduced by supporting the stator core at the node points of the stationary oval deformation mode. The cylindrical dynamic damper is very suitable to install in the turbine generator.

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This paper proposes a simple but accurate method for calculating the vibration properties of an air spring employing a circular tube to produce a damping force. Air springs are very common in rail, automotive, and vibration isolation applications, because they have many advantages over metal springs. Air spring dealt with this study consists of two tanks and a circular tube which connect them. By using the circular tube, the reservoir tank becomes more flexible, and the application range of an air spring extends. However, the vibration prediction is difficult, because the fluid flow in circular tube is very complex. In addition, it has two resonance peaks though mass is one. To solve these problems, we propose the analytical method and theoretical equations that predict vibration properties of an air spring accurately. To validate the utility of theoretical equations, the theoretical values are compared with experimental values. As a result, it has been become clear that the vibration prediction of an air spring is possible if the amplitude is small.

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In this study we propose a design procedure of a three degree of freedom vibration isolator supported with four air suspensions with slit restrictions and reservoir tanks. Since an arbitrary oscillating mode of the foundation of the three degree of freedom vibration isolator corresponds to a rotating motion around its instantaneous center axis, the oscillating mode can be describe by using a distance from a center of mass of the supported mass to its instantaneous center axis and an attitude angle of it. We use a design concept of minimizing standard deviation of amplitude against external disturbance random vibrations of foundation. To minimize standard deviation of amplitude of the supported mass, the optimum damping ratio which minimize the standard deviation of amplitude of the supported mass under the condition of rotating oscillating has to be chosen when the natural frequency of the parallel mode is lower than that of the rotating mode. In this case, the optimum damping ratio for the rotating mode of higher mode should be chosen. Although a structure of the proposed vibration isolator is more simple than that of a conventional vibration isolator with air suspensions and viscous dampers, the amplitude of the optimized proposed vibration isolator is larger only 5% than that of the optimized conventional vibration isolator in case of the volume ratio of air suspensions of the proposed vibration isolator is 0.9. From this fact, it can be said that the proposed vibration isolator is useful.

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This paper deals with dynamic responses of a finger protected by absorbers under impact forces. Restoring forces of a finger and absorbers are measured using Levitation Mass Method proposed by Fujii. In this paper, we carry out numerical analysis of dynamic response for the finger protected by the absorbers under same conditions with the experiment using LMM. The absorbers and the finger are modeled using nonlinear concentrated springs with nonlinear hysteresis. This nonlinear spring is connected to the levitated block, which is modeled by three-dimensional finite elements. The experimental data are compared with the calculated ones using our proposed FEM.

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This paper describes the dynamic characteristics based on microtremor measurement data concerning a high-rise steel building. The object building which was completed in October 1998 is 120m height and rectangular plan. Microtremor measurement is continued periodically in the building. The acceleration and velocity of measurement data in two horizontal directions and torsional direction are analyzed for natural frequencies and damping ratios on 1st mode to 4th mode. The changes along passages and the dispersions of those dynamic characteristics in microtremor are studied. And the relations between vibration amplitude and damping ratios in free vibration waves by manpower excitation are discussed.

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This report is a basic study of a vibration control device using collisions of mutual vibrators. A device consists of double vibrators made of a cantilever beam and a tip mass. Transient response of a primary system is suppressed by the vibrators because the vibration energy of a primary system is dissipated by collisions of the vibrators. In this report, the vibration control effect of this device is examined experimentally. In addition, combination of the vibrators ,which achieve the good vibration control effect, is examined by both of the simulations and the experiments.

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The authors have been developing rails for hand straps (RHSs) to improve rigidity of railway vehicle carbodies. The RHSs have been designed for a certain commuter type railway vehicle, and the effects have been verified with the excitation tests on the rolling stock test plant. In this study, RHSs improving damping characteristics are newly proposed to directly reduce the bending vibration of the carbody. Finite element model corresponding to the test vehicle is produced and the performance of the RHSs is evaluated in this model. The simulation results show that the RHSs installed with viscoelastic material successfully reduce acceleration power spectral density (PSD) on the carbody independent of the position in the carbody.

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Various semi-active control methods have been proposed for vibration control of civil structures. In contrast to active vibration control systems, all semi-active control systems are essentially asymptotically stable because of the stability of the structural systems (with structural damping) themselves and the energy dissipating nature of the semi-active control law. In this study, by utilizing the above property on the stability of semi-active control systems, a reduced-order structural model and a semi-active control law are simultaneously obtained so that the performance of the resulting semi-active control system becomes good. Based on the above fact any semi-active control laws derived from some models stabilize all real-existing structural systems that have structural damping. It means that the difference of dynamic behaviors between the real structural system and the reduced-order mathematical model in the sense of the open-loop response is no longer an important issue. In other words, we do not have to consider the closed-loop stability, which is one of the most important constraints in active control, in the process of the reduced-order structural modeling and the semi-active control design. We can only focus on the control performance of the closed-loop system with the real structure with the (model-based) semi-active control law in obtaining the reduced-order model. The semi-active control law in the present study is based on the one step ahead prediction of the structural response. The Genetic Algorithm (GA) is adopted to obtain the reduced-order model and the semi-active control law based on the reduced order model.

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It could is difficult for engineers to precisely predict the stiffness of columnar rubber isolators because of strong nonliealities in dynamic and static stiffness. For example, static stiffness may change owing to the Mullins effect. Estimation methods for predicting the stiffness of rubber isolators without trail manufacturing will be useful for engineers. The purpose of this study is to establish a method for predicting the static stiffness which includes nonlinearities caused by the Mullins effect and load dependencies. The proposed method is to estimate the static stiffness of rubber isolators by FEM analysis in which rubber isolators are modeled by hyperelastic elements based on the neo-Hookean law. Analyses were conducted to simulate deformations of the rubber isolators in biaxial load tests. The analysis results are close to the experimental data. It was verified that the proposed methods can estimate the static stiffness of rubber isolators which could change by the Mullins effect and load dependencies.

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Vibration control device and vibration isolator that have effectiveness on earthquake have been pointed in Japan. This study focuses on vibration control panel using Super-plasticity Plastic. Purpose of this study is research and development of vibration control device that can set existing buildings easily and with low cost. Vibration control device on this study consists only of panel made from Super-plasticity Plastic and set up on pillar of residential frame by bolts or nails. It is assumed that the panel converts vibration energy into plastic energy by deformation of frame. This method has possibility of spreading earthquake-proof buildings. Stiffness and displacement on around yield point of vibration control panel computed to earthquake response analysis by application of stress analysis using 3D wooden frame model with ANSYS. Shape on constricted part of panel is trapezoid, semicircle, rectangle and triangle on this analysis to examine effect of shape on stiffness and displacement on around yield point of panel. As a result, rectangular constriction fitter than the others shape for vibration control panel. Moreover, reduction in thickness on constriction has a good effect for vibration control. From the result, earthquake response of wooden house set vibration control panel having rectangular constriction analyzed with MATLAB to look into performance of the panel. Wooden house model setting 30,50,100 panels on every layer given BCJ Level 1 and Kobe NS earthquake wave. The thickness on constriction of these panels is 1mm. As a result, these panels are low effectiveness for vibration control device.

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Recently, the viscoelastic dynamic vibration absorbers(VDVA) are being studied. The VDVA consist of a mass and a viscoelastic element. The almost studies on VDVA was optimization of the amplitude of a main system subject to the parameters of dynamical properties of the model used in the VDVA. But it is difficult to obtain a viscoelastic material which has the optimum values of the parameter of dynamic properties. The VDVA using a polymeric material which viscoelasticity is known can be optimized subject to a shape parameter of the material. It is, however, known that the natural frequency of the main system which demonstrates the most favorable vibration reduction performance with the optimized VDVA is limited to near a certain frequency. In this study, the VDVA which combined the polymeric materials of two kinds of viscoelasticity of which frequency characteristics have been given by the fractional dynamic model, are proposed and optimized subject to two shape parameters of the materials. Used polymeric materials are acrylic rubber, chloroprene rubber, and isoprene rubber. As a result, the natural frequency range of the main system which demonstrates the most favorable vibration reduction performance was expanded. With the national frequency range was 2Hz to 400Hz with acrylic and chloroprene rubber, and 2Hz to IkHz with acrylic and isoprene rubber.

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This paper describes vibration analysis using finite element method for box consisting of elastic plates and damping layers connected by nonlinear concentrated springs. The restoring force of the springs have cubic nonlinearity and linear hysteresis damping. Finite element for the nonlinear springs are expressed and are connected to the elastic plate modeled by linear solid finite elements in consideration of complex modulus of elasticity. Further, the discretized equations in physical coordinate are transformed into the nonlinear ordinary coupled equations using normal coordinate corresponding to linear natural modes. This transformation yields computation efficiency. We evaluate the influences of the damping layer on the linear/nonlinear impact responses. Moreover, we also investigate the influences of stiffness for the bottom plate in the box on the impact responses.

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A variable damper applying Magneto-Rheological (MR) Grease was designed and its performance was also investigated, and the dynamic characteristics of the model structure with MR Grease damper were measured. MR fluid is known as one of functional fluids, whose rheological properties can be controlled by the applied magnetic field strength. MR damper has attracted much attention as the semi-active control device. MR fluid is composed of micron-sized magnetic particles and a carrier oil such as mineral oil or silicon oil. But the particles dispersed in the fluid would precipitate and make sedimentation due to the difference of density. In order to reduce or avoid the sedimentation of the magnetic particles in MR fluid, grease was introduced instead of base oil and MR grease was developed. In this paper, MR grease was adapted to a cylindrical damper, and its properties were investigated. Furthermore, the frequency responses of the model structure equipped with MR Grease damper were measured.

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Damping of polyarylate fiber reinforced plastics is analysed experimentally using a cantilever beam test specimen and an impulse technique. The experimental results are compared with damping properties of CFRP. It is recognized that polyarylate fiber reinforced plastics have higher damping capacity than CFRP. Next, the effects of the stacking sequence of the Polyarylate-Carbon hybrid composites on damping properties were examined. From result of vibration tests, polyarylate-outside clustered configuration gives higher damping properties.

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The seismic safety should be constantly considered for mechanical, architectural and civil structures in Japan because of one of severe quake-prone countries in the world. The aseismic construction, seismically isolated structure and response control structure have been applied to the several structures for upgrading of seismic safety, and then the design technique for large scale structure in the current situation is close to standard range in recent years. However, the quake-proof technique for the smaller scale structure such as a detached house, server rack and art and craft has not yet been in the development stage until now, and especially there is a problem in the damping element in the practical stage because the downsizing of damping element is often difficult to be adapted to design specification such as a performance, a cost, a mechanism and so on for comparatively small structure. In this study, the urethane material has been developed to use as a damping element in the response control device. The newly urethane gel material is compounded to become the characteristic that a spring element in the material to minimize the effect against the structural rigidity. This paper describes the efficiency of newly developed urethane gel material as a damping element is considered from several material characteristic evaluations and basic mechanical characteristic investigations.

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"Flexible Liquid Damper" is a new concept of a vibration control device. This damper is simple, but the damping mechanism underlying its great damping capacity has not been clarified. It is conducted to analyze the mechanism with the general-purpose computational tool "ANSYS", by creating an analytical model of the damper to simulate the test results. From the results, the damper model shows similar damping effect of the experiment, and damping effect is influenced by the damper motion. However, the liquid filling in the ball does not move with its own specific motion, and the natural frequency of the damper is regarded dominant to the damping mechanism. As the result, the damper has two natural frequencies on its upper part and the lower part. Also, a peak of the damping ratio matches to the natural frequency of the analytical model. Finally, the flexible liquid damper is modelled as a 3-DOF model, and it confirms the flexible liquid damper is a kind of dynamic absorbers.

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BTA deep hole drilling is used for producing holes of high aspect ratio. In this process, a chatter vibration sometimes occurs and a rifling mark is formed on the surface of the hole. The generating mechanism of the rifling mark in BTA deep hole drilling process has been studied as a self-excited vibration caused by time delay. As a countermeasure, the authors analyzed the effect of the BTA machining head which has three guide pads theoretically, and suggested the optimum angle to prevent the pattern formation. However, the experimental approaches for the pattern formation phenomena in BTA deep hole drilling and its countermeasure have not been established yet. In this paper, the pattern formation phenomena using the normal tool are examined and the preventing method by an additional guide pad is evaluated in the experiments.

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A control method has been developed to always excite a multi-degree-of-freedom system efficiently at a resonance frequency. When an excitation point corresponds to a vibration detection point in the multi-degree-of-freedom system, a phase lag at a resonance frequency and a phase lead at an anti-resonance frequency alternately appear in the vibration characteristics, and the phase lag becomes 90° at all the resonance frequencies. Therefore, if a controller that has a phase lag of 90° and a constant gain in a wide frequency range is used, self-excited vibration is generated at all the resonance frequencies. The self-excited vibration mode in the multi-degree-of-freedom system with local feedback control can be freely switched by dynamic stimulation. However, it can be also disadvantage in the point of changing against the desire. In this paper, a cross feedback control is added to the local feedback control to excite and stabilize the self-excited vibration modes. The cross feedback control mutually exchanges control signal between adjacent local feedback controllers. Giving the sign of the cross feedback gain corresponding to natural vibration modes can assist formation of the self-excited vibration modes. At first, we verified all the natural vibration modes are excited by adding cross feedback control. Additionally, we verified the desired natural vibration can be maintained against a disturbance. Finally, we verified amplitude of the vibration is maintained against changing mass and dumping.

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In previous studies, a newly developed stability analysis method based on the existence condition of boundaries between stable and unstable regions was applied to contact rotating systems in which all time delay are the same in order to analyze pattern formation phenomena. This analysis method can be carried out efficiently and accurately without the need to obtain characteristic roots. In this report, we attempt to apply this analysis method to a system including different time delays. The effectiveness of the proposed method is then verified with results calculated numerically by comparison with exact results of general method using characteristic roots from an example of 3 DOF system with 4 rolls, which comprises two viscoelastic rolls with different diameters leading to different time delays.

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The present paper deals with flow simulations of granular materials moving inside container using Cellular Automata (CA). CA is a class of computer modeling techniques, which consists of discrete unit elements arranged uniformly on spaces, each of which can vary within a finite set of values to express the physical state of the components of the system. The time of evolution of the element state is performed synchronously according to local neighbor rules, instead of governing equations, taking into account the state of the element itself and its nearby elements. In this study, the damping characteristic of a granular damper is investigated numerically by DEM and also by Cellular Automata model, where a container incorporating granular materials is attached to the mass of one-DOF vibrating system. By discretizing the space inside container and limiting search range of the particle interaction within neighboring site, and also by simplifying the impact dynamics of particles, the proposed CA model can greatly reduce calculation time while keeping computational accuracy as much as those can be obtained by the DEM model.

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CAD, CAM and CAE play an important role in the industrial design, and the importance of the education of CAD/CAM/CAE has been recognized at Chubu University. For the purpose of educating design engineers in practical applications, the education of CAD/CAM/CAE has been carried out to students in the faculty of technology with the support of the program for promoting high-quality university education of Japan ministry of education. Two classes in CAE are introduced in this report. The one is a class using SolidWorks (COSMOS), and the other is a class whose contents are the macro CAE using the finite element method and the micro CAE using the molecular simulation. In addition, the practical education through the 3D-CAD is presented.

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In recent years, renewable energy is used to generate an electric power. To design a small electric generator is a complicated procedure for non-specialist. This paper presents a procedure for design of small electric generator (100[w] to 500[w]) by free CAD and analysis software. The proposed method and procedure was confirmed by trail production of an electric generator. The consequences of electric generation capacity by free software are equivalent to results obtained by paid software. The design time has been decreased by using standard dimensions of components. The combination of standard dimensions and design procedure is sophisticated for novice designer and students. The proposed design procedure by using free CAD and analysis software for a small electric generator was found to be reliable and significant. Therefore, this method and procedure can be utilized for academic purpose by students and beginners.

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An example of engineering design process in a research project of Engineering Clinic Program (ECP) at Faculty of Global Engineering, Kogakuin University, is reported. In ECP, some students make a team to tackle the research project provided by a company. Professors and researchers from the company (liaison) join the team as advisors and they teach the students about basic engineering for the project. The students study the background of the project and make clear on the target and the constraints. Their ideas are examined by using CAE software and the experimental equipment is designed by 3D-CAD. The students show their solution to the project with the theoretical and experimental results, and they learn engineering design process through the project activities.

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Recent years, a system design method based on the idea of 1D-CAE is proposed. 1D-CAE provides the idea to perform the system design in manufacturing effectively and efficiently. These ideas realize the design site of manufacturing in a natural way. However, it is not a situation in which the idea can be educated in the field of education since the idea does not provide as a scholarly framework. Therefore, based on the idea of 1D-CAE, we aim to the development of educational tool that can realize a part of these ideas through an example of control system design. This paper introduces an example of development of educational tool.

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The emergency gas turbine generator of lOOOkVA will be set up in MOX fuel fabrication facilities in Japan Nuclear Fuel Ltd. In order to confirm the integrity of the generator at earthquake, vibration test was carried out by using three dimension shaking table. The seismic wave for the test was settled considering the dynamic seismic force calculated by performing dynamic analysis using the basic earthquake ground motion for Class S equipment. As a result of test, no abnormal event was observed in various testing conditions. Also, the acceleration in which the function of the generator had been confirmed was identified.

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The frictional behaviour is effective for dissipating seismic energy. Therefore, in recent years, the installation of a frictional isolator in industrial facilities has been investigated. However, the seismic response of the friction system is obtained only by non-linear time history analysis. A great deal of time is required for non-linear time history analysis. The present study deals with the easy estimation of seismic response for friction system. In the previous study, the authors proposed a response spectrum for 1-dof system with friction. This paper shows the validity of friction response spectrum by vibration test using the experimental model of 1-dof friction system. The difference of seismic response between numerical and experimental results is sufficiently small. Therefore, friction response spectrum can simply estimate the seismic response of a 1-dof friction system.

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The purpose of this paper is to propose one analytical method to make stochastic floor response spectra in order to easily estimate the dynamic characteristics of secondary system such as piping, equipment and so on, mounted on a structure owing to an earthquake. Because of the increase of uncertainty at earthquake level, the design level for earthquake is tending upward. This is implying that the aseismic design of secondary system based on elastic design becomes more difficult from the viewpoint of economic design. Thus, as a first step, this paper derives the stochastic floor response spectra in consideration of a simple nonlinear design and/or a seismic risk analysis in future. The nonlinear properties of the secondary system are modeled in terms of an equation of motion which linearly involves the auxiliary variable as part of the restoring force and the auxiliary equation which describes a nonlinear relationship. Total equations including the auxiliary equation are linearized using a stochastic linearization technique. Then executing the statistical calculation to obtain the non-stationary variance relating to relative displacement of secondary system and utilizing a proposed idea to estimate the extreme value, finally the stochastic floor response spectra can be derived. The analytical results are compared with those by Monte Carlo simulation.

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Elasto-plastic deformation decreases maximum seismic response compared with elastic deformation due to hysteresis damping. In this study, we discussed elasto-plastic behavior of components by calculating resonant curve and elasto-plastic response spectrum obtained from single-degree-of-freedom system. As a result, we demonstrated that the allowance of plastic deformation significantly reduced yield strength demand of components with response amplification. For example, if ductility ratio of 2 is allowed at elasto-plastic system with stiffness ratio of 0.2, yield strength demand tends to decrease to the strength corresponding to Zero Point Acceleration (ZPA) on building floor multiplied by mass. Elasto-plastic response spectrum is less sensitive to the natural frequency compared with elastic response spectrum. And the evaluation using elasto-plastic response spectrum might be useful even if dead load is applied to elasto-plastic system. Moreover, we discussed seismic evaluation method using elasto-plastic response spectrum and suggested that the evaluation method using static load determined from elasto-plastic response spectrum.

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In this study, the seismic responses of three disks and two shafts are evaluated analytically. In an analytical model, the disk-shaft system is treated as two elastic shafts with three rigid disks, and the shafts are supported by fluid film bearings. Furthermore, the gyroscopic effects of disks and the fluid forces due to fluid film bearings are considered. The equations of motion are derived for the translational and rotational motions. The displacements of the centers of the disks and the shafts are evaluated by numerical simulations when the system is subjected to horizontal and vertical excitations. At first, the response behaviors of rotating disks without base excitation are evaluated, and at second, the effects of sinusoidal base excitations are investigated. Finally, the response behaviors of this system subjected to seismic waves with various frequencies are evaluated. The results for the different seismic wave inputs are shown here.

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A number of artificial earthquake ground motions compatible with time-frequency characteristics of recorded actual earthquake ground motions as well as the given target response spectrum are generated using wavelet transform. The Coefficient of variation (C. O. V.) of maximum displacement, maximum velocity and maximum acceleration in elasto-plastic SDOF systems excited these artificial ground motions are numerically evaluated. The C. O. V. based on different time-frequency characteristics of artificial ground motions, different input intensity and different natural periods of SDOF systems are compared. The trajectory of mass around maximum displacement and the variances of displacement with maximum displacements are shown. It is recognized that the C. O. V. become large as input intensity is large and as natural period is small. It is also recognized that the variances of displacements jump and reach the maximum value at the moment occurred plastic drift in displacement. And the fluctuation of variances of displacement fairly corresponds with the fluctuation of maximum values of displacement.

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A load combination method for seismic response calculation of piping systems with friction characteristics to multiple support excitations is presented. This method has an advantage, such that the cross-correlation among support excitations and "response reduction factor" due to friction are taken into account by use of a stationary random vibration theory approach. This method is supplied to various correlation cases of two support excitations and friction characteristics and the maximum responses of piping is calculated. From these calculation results, it is clear that the maximum acceleration responses of nonlinear piping systems can also depend on the cross-correlation among support excitations and can be reduced due to the friction effect. Finally, the conventional equation of the response reduction factor and the maximum response calculated by the proposed method are presented for practical use.

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This paper deals with vibration displacement prediction formulae based on energy balance for boiler structures. The boiler structure is a coupled structure, which consists of the boiler, its support structure and seismic ties installed between the boiler and the support structure. Vibration displacement prediction formulae based on energy balance originally developed by Akiyama et al. were for non-coupled structures like multi-story buildings with elasto-plastic dampers. The formula could predict the vibration displacements using energy spectra as earthquake inputs. However the formulae could not be applied to the coupled structures like the boiler structures. Considering 1st natural mode of the coupled structure enabled us to formulate the prediction formulae for the boiler structures. The formulae developed by us were verified with time history analysis results using a lumped mass vibration model of the boiler structure.

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Generally, Mechanical structures in nuclear power generation facilities are demanded highly safe to resist earthquakes. In addition, highly safe is requested quantitatively of earthquake resistance and reasonable evaluation approach. This study uses energy as an evaluation approach. Recently, Energy Balance Method is paid attention to a new design and evaluation method. The study is used and constructed the extended Energy Balance Equations. Multiple degrees of model need to propose the new method. The new method proposes "method by the matrix", "method for paying attention to each mass", and "method for paying attention to the mode of vibration". In this report, the modeled mechanical structure is failed by shaking experiments. In addition, an experiment is using a strain gauge to examine the transformation of the mode of vibration. A strain gauge is set up five places. The experiment inputs a random wave and changes the excitation condition. This result, the first mode has a big strain in test piece bottom. Second mode has a big strain in the first mass and the test piece bottom.

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Poles of overhead contact line are designed based on the earthquake resistant guide, but a line hardware or an electric wire often breaks in middle scale of earthquake. In order to analyze the dynamic characteristics of overhead contact equipment under the condition of earthquake excitation, we developed 3-dimensional dynamic simulation method of overhead contact system. Moreover, we carried out bending and stretching tests of stranded conductors and exciting tests of concrete and steep-pipe poles. From these results, it is confirmed that the real bending rigidity and the bending stress of a stranded conductor is lower than that of a single wire model, and so on. This paper describes the vibration displacement and the material stress of the overhead contact lines and feeders, etc. caused by the assumed earthquake. We propose the earthquake-resistant performance and the improvement methods of overhead contact systems.

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Maintaining various city functions during an earthquake is very important. However, the concrete earthquake measures for preserving function of important facilities which constitute these city functions have not been clarified. Medical facilities have being focused on as its importance aiming to improve its seismic performance. In order to verify what occurs when existing medical facilities are hit by a large-scale earthquake, the full-scale shaking table tests for the medical facility had been conducted and the results of the shaking tests had been reported. There, the damages of the isolation structure being hit by the long-period ground motion and the base-fixed structure being hit by the short-period ground motion were clarified. Measures to prevent the variety of earthquake damage which became clear by the tests were examined, and full-scale shaking tests on medical facility prepared for the measures were conducted again to verify its function of maintenance performance. This report describes the shaking tests and the results.

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It broke out the Great Tohoku earthquake in March 2011 was enormous damage in Japan. Japan is well known for earthquakes. Recently it has been reported that long-period seismic waves is danger for high-rise buildings by both the progress of seismograph and increasing in their damage. It has been concerned that capital territory will be expected to occur in the future. Now retrofitting viscos damper as a kind of seismic countermeasure of high-rise buildings is adopted. But it has durability issue that excessive temperature rise of fluid in viscos damper because duration of long-seismic waves is quite long. Therefore we focused on the problems in the present study, we proposed Viscos-Friction Hybrid Damper which is connected existing viscos damper and friction damper with series, to come down absorbed quantity of energy and to progress of durability. In this report, we proposed Viscos-Friction Hybrid Damper and conducted element test which used the test damper to confirm fundamental behavior of it. As a result, it was confirmed that the test damper was satisfied development concept Viscos-Friction Hybrid Damper.

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The authors develop a circular arc shaped spring damper in order to keep soundness and reduce damage wooden structure when the earthquake is happened. The spring damper is composed of viscoelastic material which is sandwiched by two steel plates. It is able to strengthen stiffness by the steel plates, and give a damping by viscoelastic material. The damper is available for not only wood houses, also old structures such as castles and temples, since it can be attached easily. In this paper, in order to confirm effects of bearing wall and vibration reduction under earthquake, shear strength tests and seismic vibration tests using a real scale bearing wall are carried out. A test frame of the bearing wall has 2.73 m high and 1.8 m wide. The test frame is horizontally loaded by using an actuator, and force and deformation are measured. Shear strength of the bearing wall is estimated. Next the test frame is horizontally shaken by earthquake using a shaking table. The response accelerations and relative displacements are measured, and the effect of vibration reduction is confirmed experimentally. Finally, a feasibility study about the spring damper is confirmed.

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