In this paper, a vertical seismic isolation device using bilinear spring mechanism and a ball screw type damper was made, and the effects of vibration isolation were substantiated experimentally and numerically. The experimental and calculated results showed that the vertical isolation table has the natural frequency of 0.54 Hz and the static deflection of 172 mm. The maximum response acceleration decreased to about 1/2 compared with the maximum input acceleration.

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This study aims at research and development of the intelligent seismic isolation system using air bearings as isolation device and earthquake early warning as trigger. A superstructure is supported by air bearings installed at the foundation. Compressed air generated by compressor is gushed from the air bearing and the air film is generated between the air bearings and the ground surface. Then structure floats from ground and no seismic motion is transferred to superstructure. In this paper, principle of isolation and isolation performance that is investigated by numerical analysis are described.

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This paper describes the research and development of a new seismic isolation system using vertically utilized elastic and elasto-plastic coiled springs, and discusses analytical model for coiled spring. The horizontal static tests were performed to evaluate the restoring characteristic and the mechanical model of elastic and elasto-plastic coiled springs. The characteristics of these coiled springs such as transverse stiffness and hysteretic damping and the validity of the analytical model were clarified through the static tests. Furthermore the response analyses based on the restoring force characteristics of experimental results were carried out to assess the isolation performance of this system.

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The traditional seismic isolation system is composed of sliding bearings or lead rubber. It can effectively isolate the horizontal earthquake motion, but it can not isolate the vertical earthquake motion effectively. In this paper, an active water hydraulic seismic isolation system is proposed to improve protection human lives and building's integrity against large earthquake. This paper is divided into four sections. Firstly, the design principle of the seismic isolation system is described. Then simulation is conducted to calculate the parameter for a single-family house seismic isolation device. Finally the basic experimental setup is constructed and experimental results show the good performance of the water hydraulic system. From the calculation results and experimental results, it can be conclude that the proposal of the seismic isolation device is feasible.

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This paper deals with an isolation device by using friction force. An isolation device decreases response acceleration and external force. Therefore, earthquake damage is reduced. However, an isolation device has a demerit for large relative displacement. The purpose of this research is to decrease the relative displacement by using the friction force. Then, an analytical model in consideration of the friction force is proposed, and a simulation is analyzed with well-known earthquake waves. Consequently, it is thought that optimal friction force exists, and this force decreases both the response acceleration and the relative displacement. This is considered to change with the properties of earthquake waves. Then, the model to which friction power is changed in linear was proposed from the relation with the compression spring attached in the lower part by changing the angle of a friction surface. An experimental device is made under the same conditions as the proposed analytical model. The experimental results are compared with the analytical results.

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This paper deals with reduction of response acceleration and horizontal relative displacement by using a frictional force for a seismic isolator. In this research, the seismic isolator that used the compression spring was prosposed. As a result of conducting the analysis and the experiment to this model, it was shown that response acceleration and relative displacement are reduced to some extent. In order to reduce them more, analysis was carried out in the condition to which a coefficient of friction is changed by relative displacement. As a result, response acceleration and relative displacement were reduced effectively. However, it is difficult to change the coefficient of friction actually. Then, by changing the angle of a friction side, frictional force is changed and the experiment is conducted.

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It is important to protect manufacturing or inspection devices from disaster by eartyquake in terms of business continuity plan. One of the most effective techniques is seismic isolation floor. We made a prototype setup of actively controlled seismic isolation floor which consists of servo motor and ball screw and it can be installed additional stiffness to imitate actual pipes or cables connected to the devices. We examined about the performance of the isolation floor on the shaking table and this isolation floor performed smoothly by canceling the resisting force. The resoponse of both acceleration and displacement of the isolation floor can be reduced by active control method of skyhook control and optimal control.

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It was reported that a number of valuable objects such as antiques had fell down and been damaged when the Mid Niigata Prefecture Earthquake in 2004 had occurred. This paper proposes a three dimensional seismic isolator which can keep the isolator stage horizontal while the stage can move in the vertical direction. The isolator has been developed in the aim of protecting relatively small but valuable items such as works of art in museums against earthquakes. Two linkages have been employed for the mechanism to prevent the isolator stage from tilting, and the validation of the proposed mechanism is performed in both simulations and experiments. It proves that the proposed seismic isolator can reduce the magnitude of acceleration approximately to one fifth of that of the input in both horizontal and vertical direction, which can also reduce the possibility of overturning of objects.

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High Seismic safety reliability is required for nuclear power plant. Usually equipment and piping installed in nuclear power plant are assumed to be rigid, and are designed by using static seismic load. However seismic load is cyclic load, thus it is very important to grasp dynamic vibration characteristics. In this paper, forced vibration experiment by artificial earthquake wave is carried out then experimental results are evaluated from the viewpoint of the Energy Balance that is varied method for dynamic evaluation.

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In this Study, vibration characteristics of mechanical structure having high natural frequency is investigated from the viewpoint of energy balance equation. Usually, mechanical structures having high natural frequency in a nuclear power plant is designed statically and elastically. However it is very important to grasp seismic safety reliability dynamically by considering cyclic load. This paper describes investigation into vibration characteristics of SDOF model under sinusoidal wave excitation from the viewpoint of energy balance. The energy balance equation is one of valid method to evaluate cyclic vibration response such as seismic load.

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In new measurement technique to propose, displacement by bending vibration of piping which vibrates using multiple laser displacement sensors is measured, and vibrational stress is obtained by calculating the strain produced from those displacement differences for piping. This measuring instrument is a non-contact system, and a miniaturization and short-time measurement of equipment are easy. This paper deals with the concept of the vibrational stress measurement technique, the theory of the measuring method, and the procedure using three sets of the laser displacement sensors. Furthermore, using a cantilever model, vibration experiments are conducted, displacements and strain are measured. Next, the comparison with the stress by using the displacement of experiment based on this technique and the stress from the strain of experiment is performed.

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A lot of damages have been reported due to fatigue of machine vibration during plant operation in nuclear power plant. The development of vibration measurement and stress evaluation that can operate quickly and easily is on demand. The purpose of this research is to develop technique which measures vibrational stress immediately using a laser displacement sensor. This paper deals with the concept of the vibrational stress measurement technique, the theory of the measuring method, and the procedure using three sets of the laser displacement sensors. The stress of the displacement and the stress of the strain are compared.

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In this paper, the optimal seismic design methodology which can consider the structural integrity of both the piping systems and the elasto-plastic dampers are developed. This methodology employs genetic algorithm and can search the optimal conditions such as the supporting location and the capacity of the dampers. Four kinds of evaluation functions arc considered. As the results, it is found that the optimal seismic design methodology proposed here is very effective and can be applied to the actual seismic designs for the piping systems supported by the clasto-plastic dampers. And it is shown that this methodology can be also applied to the piping systems exposed to the actual earthquake waves which have various frequency characteristics.

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Presently, mechanical structures in nuclear power plant are usually designed statically and elastically. However, it is very important to grasp dynamic seismic safety reliability especially in unexpected severe earthquakes. Therefore new evaluation method that considers dynamic strength is required. In this study, dynamic ultimate strength is investigated from the viewpoint of energy balance. Energy balance is a method valid to evaluation of cumulative damage. Vibration experiment that induced experimental model to fatigue failure is examined, and the experimental result is arranged by energy balance method. Consequently a relation between fatigue failure and input energy to experimental model is confirmed.

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The regulatory guide for seismic design of nuclear power plant has been vastly revised at several fields. Main items under revision are observed such as the requirement of making appropriate concern for the dynamic coupling effects of horizontal and vertical components of earthquake, and the consideration of probabilistic risk assessment against the uncertainty of earthquake. The purpose of this paper, therefore, is to estimate the stochastic responses of multi-degree-of- freedom structure with closely spaced natural frequencies under the consideration of the correlations between multi components of earthquake. For this target, one mathematical model is developed in order to analytically evaluate the effects of correlation between components of input, and the stochastic vibration analysis is executed based on FEM-based eigen mode analysis and transition matrix method. The analytical results are compared with those by Monte Carlo simulation.

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In recent years, the vibration control devices for the detached house has been attracted attention. However, the detached house has the first natural frequency at high frequency band. Therefore, the deformation transmitted to damper becomes small, and the damper have to be designed to obtain a desirable performance against such small amplitude vibrations. Moreover, the cost of manufacturing dampers should be lowered to be used widely. In this study, the damper using the amplification mechanism has been developed to address the above issues. The experiment was performed to investigate the property of the damper, and the earthquake response analysis based on the restoring force characteristics of experimental results was carried out to evaluate the performance of the damper.

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In this paper, a new vibration control device called pendulum tuned mass damper (P.T.M.D) is proposed to reduce an ordinal house vibration. In recent years, three stories houses are built increasingly in the urban areas to obtain wide living space in a narrow land area. 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. It seems to invite the dangerous situation under the large earthquakes. The proposed P.T.M.D acts on the principle of lever mechanism and can be placed between the first and second floor. In addition, it has an adjustable mechanism to adapt to various specifications of these houses. Effectiveness of the P.T.M.D is demonstrated experimentally by controlled results using frequency, time and seismic responses.

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Suppression performance of active mass damper for vibration structures is decreased by the limitation of the active mass operational area. A switching vibration control strategy of active and passive mass damper based on dynamic energy of vibration structure had better performance against the limitation. However, it was difficult for the strategy to decide the most suitable threshold uniquely by trial and error. In this paper, it is considered to show the suppression performance of the strategy against earthquakes including various frequency modes in consideration of the structure's dynamics by simulations and experiments.

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This paper presents a control design method considering both non-linear characteristic of a structure and non-stationary characteristic of earthquake motions for the purpose of reduction of the building response subjected to earthquake. A single-degree-of-freedom whose rigidity is bi-linear hysteresis during non-stationary disturbance such as earthquake is dealt with and the optimal control system is obtained by applying the equivalent linearization technique. First, the equivalent linearization of the non-linear structure is performed by using the 2nd moment of the building responses such as displacement, velocity, acceleration, etc. Next, a non-stationary model of ground motions is shaped from white noise. And an augmented model is made by including the equivalently linear model of non-linear structure and the non-stationary disturbance model. Finally, the optimal control system for the augmented system is obtained. In order to investigate the usefulness of the proposed method, computer simulation is carried out and this method is verified.

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This paper presents the free vibration analysis of fiber reinforced plastic composite plates. For this purpose, the governing equations are formulated for a cross-ply laminated, simply-supported rectangular plate based on Classical Lamination Theory (CLT), First-order Shear Deformation Theory (FSDT), Higher-order Shear Deformation Theory (HSDT) and Discrete-Layer Theory (HIT), respectively In the numerical examples, natural frequencies and specific damping capacities of the plates with different stacking sequences and dimensions are calculated numerically by assuming complex elastic modulus. Finally the applicability of each analytical model for damping analysis is studied by comparing with numerical results obtained respectively.

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This paper studies the optimization characteristics for linear and nonlinear vibration of laminated composite circular cylindrical shells. For this purpose, the backbone curve equation for primary resonance is derived analytically by using the Galerkin's method and the harmonic balance method. In optimization, fiber angles of each lamina for a symmetrically balanced laminates are taken as discrete design variables, and nonlinear and linear frequency are taken as object functions to be maximized simultaneously. In numerical calculations Multi Objective Genetic Algorithm (MOGA) with Fonseca-type rank evaluation, sharing technique and elitist strategy is employed, and thus pareto optimum solutions are obtained numerically. Finally optimal stacking sequence is discussed by comparing the backbone curves obtained for the pareto solutions.

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A new design method of functional fiber reinforced plastics (FRP) materials which imitates the micro structure of bone or shell in the natural world is proposed in this work. The material has local anisotropy induced by optimally distributed short fibers. The present design method combines a genetic algorithm method (GA) with layerwise optimization concept. The first frequency of thin plates is chosen as an objective function to be maximized in the optimization and it is turned out that the present plates always give higher natural frequencies compared to conventional plates which are reinforced by parallel fibers. Moreover, it is also revealed that optimally distributed short fibers tend to be allocated with certain tendency.

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In this study, several different types of delamination (partial debonding in the adhesive layers) were introduced in carbon fiber reinforced plastic (CFRP) laminated cantilever beams and then experimental measurements and finite element method (FEM) numerical analysis and simulation were applied to free vibration of those specimens made in this study. The experimental measurement showed that first bending mode frequencies and their modal loss factors varied when delaminations were introduced in the specimens. Distributions in each laminate with delamination of transverse shear strain energy and contact pressure were also obtained by FEM and then quantitatively examined.

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This paper studies the analytical models for vibration of visco-elastic materials such as rubbers. For this purpose, the frequency characteristics of complex elastic modulus are obtained by using the spring-dashpot models and the fractional derivative models, and then the effect of parameters of the models are studied on the characteristics. Parameter identifications for the models are conducted by using experimental data referenced. Finally the applicability of the models is discussed by comparing the results from the identifications.

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This paper studies the optimization for inner rib's thickness of the shell structure of aluminum allow hollow extrusion by using genetic algorithm. In the optimization, total mass of the structure is minimized under the constraint conditions with respect to maximum deformations of the structure. The deformation of the structure is evaluated numerically by using the finite element analysis developed for tow-dimensional elasticity in the present study. In numerical calculations optimal design solutions are obtained for the structures by specifying the allowable maximum deflections of the structure, and the effect of the rib's thickness is studied from the numerical results obtained.

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An analysis for vibration of spherical shells with a constrained viscoelastic layer and metal layers is presented. In this paper, vibration damping properties of three layered spherical shells with viscoelastic material are analyzed from both of SEM (Strain energy method) and CEM (Complex eigenvalue method). Eigenvalue and eigenvector (displacement functions) are analyzed based on the Ritz method, when natural frequency, modal loss factor and strain energy are obtained. In CEM, the elastic modulus of viscoelastic material is dealt with complex quantity considering material loss factor. In SEM, modal loss factor is defined as a ratio of damping energy (strain energy consumed in viscoelastic layer) dissipated during a vibration cycle and total strain energy of the shell. The accuracy and validity of the present results from two methods are illustrated through investigation of convergence and comparison with the established results from the literature. Numerical results are presented for different parameters, such as the opening-angles, material loss factors and circumferential wave numbers.

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This paper deals with the problem of dynamic stability of composite laminated cylindrical shells under impact torsion is described. First of all, the motion of cylindrical shells under impact torsion is defined as axially symmetric motion. Following this definition, certain perturbations are superimposed on this motion and their effect on the behavior of the shell is investigated. The solutions for the prebuckling motion and the perturbed motion are obtained using the Galerkin's method. Stable regions are determined by utilizing Mathieu's equation. The inevitability of dynamically unstable behavior is proved analytically and the effects of various factors are clarified.

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Because of their high specific strength and stiffness, fiber-reinforced plastics have been used as structures in various fields, and hence the analysis of thin laminated structures is of importance. In this paper, the postbuckling behavior of composite laminated curved plates with initial imperfections, which are simply supported along four edges, under biaxial compression are examined by various methods including Galerkin's method. The inevitability of postbuckling is proved analytically, and the effects of various factors, such as the type of initial imperfection, number of layers, lamination angle, biaxial compressive load ratio, and deflection pattern, are clarified.

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Advanced fiber-reinforced laminated composite materials have been used for structural members in various fields, because of their high specific strength and stiffness. In the present paper, the thermal buckling problems of carbon fiber / epoxy (CFRP) cross-ply laminated cylindrical shells are considered. Buckling analysis is performed by assuming the buckling deformation that satisfy the boundary conditions and the equilibrium equation based on the Flugge-type expressions. The effects due to various factors such as lamination constitution, stacking sequence, number of layers and dimension of cylinders on the buckling temperature are clarified analytically.

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Finite element method using axisymmetric shell element is applied to the buckling of torispheical shells under internal pressure. The linear buckling and plastic bifurcation buckling analyses are performed on the specimens tested by Galletly and Patel & Gill. The results are compared with the calculated results by program BOSOR5 and the experimental results. The differnce in the buckling predictions of the deformation, modified flow and flow theories of plasticity is investigated.

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We propose a new procedure that is able to predict buckling pressures and failure modes under the post buckling responses for torishperical shell structures. Three torishperical shell structures experimented by Galletry and Patel & Gill were calculated by our new procedure by ABAQUS. The calculated buckling pressures and failure modes had good agreements compared with the experimental results.

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In this report, for improving the productivity and the performance of a piezoelectric pump and for reducing the cost, the vibrations of bimorph and unimorph type piezoelectric vibrators are analyzed theoretically, and their vibration characteristics are discussed by comparing the results.

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The purpose of the present investigation is to clarify the vibration characteristics of piezoelectric vibrator coated with silicon rubber. In this paper, frequency response curves of the drive unit obtain by the numerical analysis are compared with the experimental result. From the results, it was clear that the analysis results correspond qualitatively well with the experimental ones within the lower frequency range below the first resonance point but don't agree above the point. Therefore, it is indicated that the analysis is effective within the lower frequency range but it is necessary to consider the viscoelasticity of silicon rubber additionally for the higher frequency range.

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The measurement of Vibration Intensity (VI) is an effective means to identify the vibration energy flow. The vibration energy propagating the shell structure consists of the flexural component and extensional component and interacts mutually. However, when the VI method is applied to measurement of extensional VI, it has some errors caused by setting of many acceleration sensors and interaction of these components in the boundary between flat plate and curve plate. In the present paper, an attempt was made to simplify the measurement method of extensional component of VI at shell structures employing the vibration data obtained thought finite element method (FEM) analysis.

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The problem of the durability of the concrete has been brought to the public attention by railway-related accidents. The laser ultrasonic method is expected as a method of non-destructive inspection for concrete. The laser ultrasonic method has an advantage that the sensors are no need to be contact with the specimen surface. The advantage enables the automated remote inspection. In this paper, we present results of an investigation of the relation between FFT analyzed results of the waveform measured by piezoelectric transducer and the depth of artificial defect. The results show that FFT analysis enables the waveform measured by piezoelectric transducer to be of practical use in application on non-destructive inspection of the deep-seated flaw.

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This paper derives a modal expansion of structural intensity for longitudinal vibration on beams. The expansion is expressed by the superposition of modal terms expressed by the product of weight coefficients and cross-modal functions. Cross-modal function is presented by the product of two modes with or without spatial derivatives. Numerical simulation is carried out in order to verify the modal expansion derived. The expansion is also applied to calculate the structural intensity on a beam system with the other beam as a branch. The comparison of one beam system and the branch system can introduce how we can utilize the modal expansion for structural intensity to design and develop structures.

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The acoustic power radiated from the vibrating components of the high speed diesel engine such as the crankcase and gear case was examined by use of the boundary element method (BEM). It was discussed an increment of the radiated noise from the front side of the engine block due to the radiated noise from the vibrating pulley installed at the front end of the rotating crankshaft. Moreover, a simplified method was offered to determine the acoustic radiation power of the engine block using the acoustic radiation efficiencies of the engine block's eigen mode. Its validity was confirmed through the comparison with the precise BEM calculation.

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Vibration and acoustic models for carpet on automotive vehicle floor has been developed. The vibration model is expressed of by lots of sets of a spring, mass and damper on FE model. The acoustic model is consisting of sound radiated from carpet and sound transmitted through carpet, of sound radiated by panel. These models on automotive floor are verified by the comparison of the modal properties, frequency response and acoustical intensities between measured and calculated. As a result, the predicted results are good agreement with the measured on the vibration of both the panel and the carpet surface, radiated sound.

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This paper describes sound generation of a frog shaped guiro made of wood. By robbing a dorsal fin like a saw tooth on the frog shaped guiro with a wooden stick, the guiro generates the sound like a frog's voice. The relation between the impulsively exciting force and sound pressure was measured with an accelerometer and a microphone. The FEM modal analysis revealed that the frog shaped guiro had four dominant modes of vibration which could be characterized by motion of mouth of the guiro. The frequency spectrum of the sound pressure radiating from the guiro excited by sequential impulsive forces was theoretically estimated. It was then revealed that the variation of driving point mobility of the dorsal fin and amplitude of the exciting force affected to generate sound like a frog's voice.

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In order to elucidate the characteristics of rolling noise of wheel / rail system which is to be the main cause of the conventional railway noises, first the coupling vibration analyses were carried out by using an infinite length rail model with tread surface roughness and FEM model of wheel, and then based on BEM with the boundary conditions of obtained vibration responses , the acoustic radiation powers and the distribution of SPL of sound fields on both of the slab and ballast tracks were calculated for the wheels with straight , TGV-type and corrugated web. Examining the influences of wheel configurations to the rolling noise, the methods of countermeasures to reduce that noise were implied.

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Railway viaduct is one of institutes which have subject to reduce noise form it because it causes an excessive degree of noise attributable to vibrations of structural members such as floor slab. In order to develop a certain effective countermeasure, it is vital to evaluate and analysis the vibration of railway viaduct and noise from it and establish a method to predict the structure-borne noises. Therefore, we performed impact test and measurement of the noise and vibration upon train passage over the viaduct constructed for Shinkansen line. Moreover, we executed a frequency response analysis by finite element method (FEM) by applying the results of the impact test and measurement upon train passage, and calculated noise sources adjacent to floor slabs based on the solution of the analysis. As the result, it revealed that the calculated and measured values were approximately consistent in a range below 500-Hz, however deviated in a range exceeding 500-Hz. It is therefore necessary to improve the accuracy of analyses in the high range of frequency.

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Rolling noises have become an important problem of narrow-gauge railway vehicles. The noises are composed of rail noise and wheel one. By the study about the wheel noise that we performed till now, We found that the noise radiated from wheel was not only the wheel web but also the other parts. Therefore, we carry out a more detail 3D-modal analysis experimentally for a purpose of inspecting the mode shapes obtained from FEM analysis and calculated the sound power separately from each part of the narrow-gauge wheels by using 3D-BEM analysis. Furthermore, we performed modify of the wheel geometry to examine an acoustic effect. As a result, we found that the wheel which added to the thickness of the rim has the lowest sound level compared with other wheels.

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This paper proposes to reduce a heavy-weight impact noise of double floor. The magnetic levitated led using the repulsion of permanent magnet has been developed to isolate the impact force from the double floor. In the experiments, construction method of the magnetic levitated legs is investigated from the displacement of static or impact load, and the floor impact noise. The experimental results show that the heavy-weight impact noise could be reduced about 10dB in range of 32-250Hz octave band. However, the displacement of static load was increased than the traditional rubber support legs.

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This paper presents the analytical method to evaluate the impact force and engine noise induced by piston slap considering the detailed piston profile. This method is applied to examine the effect of the piston profile on piston slap impact force and frequency spectrum related to the engine noise. The tendency of the piston pin offset to abate the piston slap is compared with the measured one to confirm the availability of this method. And it is pointed out that piston movement in the vicinity of the combustion top dead center is governed by the friction moment around the piston pin and the additional piston pin offset moment induced by combustion pressure.

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This paper describes a noise reduction design of random impacted structure like a coin storage box of a coin counting machine. The sound power radiated from the box is estimated based on probabilistic model of random impact forces. The integrated sound power in frequency domain is used as an index for an evaluation of sound reduction. In this structural modification, straight dimples are added to the box so as the dimples cross antinodes of the distinguished mode of sound power. As a result of sound power measurement, it is confirmed that the proposed method is applicable to noise reduction design.

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In this paper, sound-analyzing programs for one-dimensional duct were built using the Scattering Matrix Method. This method is especially useful for the case of distributed sound sources and loop ducts. This simulation method was validated by comparing results with experimental ones of some simple one-dimensional duct, in this paper.

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This paper describes acoustic absorption property of a perforated panel and the availability as an acoustic absorbent. Improvement of absorption property of this panel under steady flow was verified and not only the normal incidence sound absorption property of this panel but the parallel incidence one were investigated. Furthermore, a method of acoustic analysis by boundary element method (BEM) which considers the acoustic damping on a rigid wall was proposed. Finally, high sound absorption property of this panel when it was applied to a duct and the effectiveness of acoustic analysis of a duct using this panel by BEM were confirmed.

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In many electric equipments or engines, noise is often generated within the cabinet and propagates through the orifice and radiated to outer space. In order to reduce noise, absorbing meteraial can be set in the cabinet. As absorbing materials are in general expensive and requiring much space compared to metal or plastic materials, efficient setting is desired. The finite difference method in time domain (FDTD) can he applied to predict sound field in the cabinet. As configurations of equipments can be well represeted by non-uniform grid, the compact finite difference on that grid was applied.

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In recent years, the weight of vehicles haw been decreased to save energy, while the light weight vehicle for reducing the weight invites low stiffness affects on driving performance of the vehicles. According to this, a road simulator utilizing a belt conveyer and an experimental vehicle with variable body stiffness are built to perform experimental research. The stiffness of vehicle body can be varied by changing a burly part. The dynamical behavior of the vehicle is measured by sensors, while the vehicle runs on the road simulator. By comparing the behaviors with different body stiffness the relation between body stiffness and driving performance of the vehicle can be identified.

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In recent years, railway vehicles are becoming lighter since it corresponds to improvement in the running speed. However, this causes the deterioration of the body rigidity, and leads to the increase in a vertical bending vibration of the body. In addition, the deterioration of riding comfort concerns to this issue, because the natural frequency of the 1st bending vibration and inverse phase vibration overlaps with human's uncomfortable sensitive frequency band. The objective of this research is to reduce these bending vibrations of full-scale vehicle by stack type piezoelectric actuators and to investigate the influence of the local deformation by larger size actuator.

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