The author had already proposed a simple second order linearized equation of motion for the axisymmetric spinning bodies such as tops. The equation contains influence of both gravity and weak friction torque. This time, it was transformed into the state equation and the transition matrix solution was derived. As a result, because loci of the angular momentum, the angular velocity, the spin axis and the contact point to the desk of the spinning body can be easily drawn, the insight to the behavier of the body is obtained. Spinning motion of a circular flat ellipsoid is also analyzed.

View full abstract

The rotational vibration by the unbalanced electromagnetic pull force in the rotor eccentricity of the universal motor is studied. In this paper, developed test equipment is described. The natural frequency of rotor system is 200Hz. And, the displacement of the rotor in the resonance was designed to be a parallel mode. The vibration of the rotor in being eccentric for non-pole direction of the stator or pole direction was examined. The effect of the unbalanced electromagnetic pull force of the universal motor for the pole direction is large. And, it is remarkable effect of AC than the direct current.

View full abstract

This paper deals with the Active Isolation System using MR Fluid. Isolation system is a one of technologies to protect buildings against earthquakes. This technology provides abilities that vibration of earthquake doesn't transfer to buildings with isolation layer between buildings and ground. In this report, the performance of FFF, which we proposed in the previous report, is evaluated and we suggest the functionalized isolation system using FFF. This system realizes to control actively the vibration transmissibility of isolation layer. Furthermore, we evaluate the performance of building restoration method using FFF.

View full abstract

Semi-active seismic isolation systems with the controllable friction damper using the piezoelectric actuators had been proposed to reduce response accelerations and displacements comparing with those of the passive systems. However it is difficult to apply this controllable friction damper to large structures, because super large piezoelectric actuators and large amplifier are needed for the mechanism. A new controllable friction damper using hydraulic pump driven by giant magnetostrictive actuators in this study. This hydraulic pump can make quick responses, and this controllable friction damper using this hydraulic pump produces large force. This paper outlines the results of the characterization experiments of the new controllable friction damper and excitation tests on the semi-active seismic isolation system with this controllable friction damper.

View full abstract

This paper presents a new seismic isolation system which is composed of two layers with a magneto-rheological fluid(MR) damper on each layer. We design a gain-scheduled controller based on H∞ theory for the semi-active seismic isolation system for a multi-degree-of-freedom structure.,so that the lower layer has a role to isolate the vibration transferred from seismic excitation and the upper layer has a role to suppress the structural vibration. By dividing the roles into two layers, it is expected that the total damping force of the traditional seismic isolation system is reduced and performance of isolation is held or improved. It is demonstrated by simulation and experiments that seismic responses by the new isolation system are compared with those by the one-layer isolation system. It is verified that the new system is superior to the traditional one and the gain-scheduled controller designed is effective for seismic isolation.

View full abstract

This paper describes isolation performance of semi-active seismic isolation system using variable damper. Recently, the relatively long period seismic waves have been observed in the various earthquakes. These seismic waves have the predominant period that is equivalent to natural period of seismic isolation structures. Therefore technology is required that supply more safety to isolation structure. A semi-active isolation system in this paper has been proposed to satisfy the requirement. Variable damper is applied to isolation system to vary damping ratio. It was confirmed by numerical analysis that this isolation system has good performance of isolation.

View full abstract

In this paper, seismic response analysis is made both experimentally and numerically for a base isolation device with pseudoelastic shape memory alloy(SMA) springs as restoring force components. Owing to the material nonliniarity and the geometrical nonliniarity, the SMA spring used in the device has well-defined softening, or "force limiting", property that can suppress the acceleration response of the superstructure by limiting the seismic force transmitted from the ground. Numerical simulations are conducted using Preisach-based SMA spring model. Then, assuming the scalability of the restoring force v.s. displacement curve of the SMA spring, seismic responses of the devices with SMA springs which have various restoring force characteristics are investigated, numerically. From their results, brief design criteria are suggested.

View full abstract

Recently, an isolation system has been required not only to be protect from structure but also to continue its functioning and we have to consider resonance of seismic isolation system in a seismic excitation having predominant frequency components. To solve this problem, we proposed the new isolation systems, which consist of air bearing and Earthquake Early Warning Information. This isolation system utilizes Earthquake Early Warning Information System that delivers some earthquake information to each receiving terminal before the Swave reaches, which has low friction properties. The operation judgment of the air floatation is done based on Earthquake Early Warning Information. This paper describes the results obtained through response earthquake analysis.

View full abstract

We proposed the floor isolation system for computer equipment in buildings. The floor isolation system is composed of two elements of bearing and restoration. The restoration is used coiled springs with elasto-plastic restoring force characteristic. This paper presents the results obtained from theoretical analyses to evaluate the isolation performance of the floor isolation system. As results of analyses, the floor isolation system could not only reduce response acceleration of the floor but also the response displacement of the floor. Therefore, this floor isolation system was confirmed to have good isolation performance suitable for a floor.

View full abstract

This paper describes the results of the new isolation system using vertically utilized coiled springs suitable for light-weight-houses. The experimental tests of using a 0.20 scale model of an isolated house and theoretical analysis were performed to investigate the isolation performance. The results showed that the restoring forces characteristics of the vertically utilized coiled springs was to be linear, the isolation system could not only reduce the response acceleration of the scale model itself but also the response acceleration with respect to the fixtures and fittings which has a wide band frequency. Consequently, The isolation system was considered to have desirable the isolation performance suitable for light-weight-houses.

View full abstract

A structural damping can be improved by installing high damping alloy in steel structures. This paper presents a fundamental study to increase the structural damping by adding high damping alloy in the steel e structure. Free vibration tests using models composed of stainless steel plate and small Mn-Cu alloy plate, and vibration analyses for the test models are carried out to investigate damping ratios and natural frequencies of the complex platee structure. From the experimental and analytical results, the effects of installation positions and installation sizes of the Mn-Cu alloy plate on the damping ratios and frequencies of stainless steel plate are mode clear.

View full abstract

A dynamic damper using Mn-Cu alloy is proposed to reduce vertical vibration of long-span footbridges. This paper presents an analytical study for evaluating effects of collision vibration of the dynamic damper weight at the stopper on vibration control performances of the dynamic damper for the footbridge. In the analysis, seismic response analysis using 2 kinds of a non-liner dynamic damper model with collision gaps and a linear dynamic damper model without collisions are carried out. Effects of collision spring constants, coefficients of restitutions at the stopper and seismic acceleration levels on the seismic control performances of the dynamic damper are evaluated.

View full abstract

In this paper, we propose a new method of designing a passive vibration control system. The standpoint is that the structure of the passive vibration control system is similar to that of a PD controller. Variable parameters of one-degree-of-freedom passive isolation device, i.e. spring and damper, are considered as the feedback gain of the PD controller. After that, frequency characteristics of the open-loop transfer function of the transformed system with PD controller are optimized in the suitable restriction by GKYP lemma.

View full abstract

The new tire wheel system which is possible to measure tire force directly is being developed. It is called Smart-Tire-System and is inexpensive. The aim is to improve the steering stability and the safety of the car. This paper discusses the effectiveness about the control system to use this system. Mainly, it describe about the control of the braking force using the information on the normal load. It showed to make an effective control possible compared with the conventional method.

View full abstract

In this paper, we design a control system of an electric power steering applying the H_∞ control theory to evaluate responses of the steering system in frequency domain. Furthermore, in order to improve transfer characteristics of the steering angle from the self aligning torque, the self aligning torque generated from the vehicle model is considered as disturbance to the steering system on the controller design. By carrying out simulations, it is verified that the controller designed is effective to improve stability of not only the steering system but also the vehicle model to inputs of the steering torque or the self aligning torque. Also simulation results show the robustness of the controller designed to variation of the vehicle speed and the mass.

View full abstract

In passive suspension for automobiles, the ride comfort and the driving stability are a trade-off relationship and many studies of semi-active suspension have been performed in order to realize a high-level performance of both aspects. In this study, a semi-active suspension system of variable stiffness and damping is dealt with. For the semi-active control system, a disturbance accommodation frequency-shaped control method is proposed in order to improve both the ride comfort and the handling performance in a higher level. Furthermore, in order to present a method of determining the weightings in the criterion by the genetic algorithm, a parameter related to the ride comfort and the driving stability is introduced. By carrying out computer simulations, it is demonstrated that the proposed method is effective.

View full abstract

In the recent years, the development of an analysis technology enabled a high-accuracy forecast of the vehicle performance. The analysis requires various data. However those data are indeterminacy in early stage. In this article, we researched the technique for forecasting the vehicle performance with a little detailed data in concept stage of development to promote weight reduction and controlling center of gravity.

View full abstract

The technique for presuming the load to the body is considered by simulating the behavior of suspension system when the vehicle runs on the assumed road. Dynamic behavior of the tire corresponding to the change in the road has the frequency response. In this research, we focus attention on the behavior in a comparatively low frequency domain, and don't think the vibration in the high frequency area. We construct the technique for predictively tuning the vehicle on the assumed road.

View full abstract

This paper presents an efficient numerical method to realize discrete models of fractional order controllers for systems containing backlash nonlinearity. The presented method is to calculate fractional derivatives and integrals on inhomogeneous time intervals which are getting longer as the operation points go back toward the initial time. It leads to the effective quality which has low computational costs and enough accuracy. A practical controller design is applied for an inverted pendulum system containing gear-backlash. The simulation and experimental results show that the fractional control system has superior performance against backlash nonlinearity and thus the backlash vibration can be suppressed.

View full abstract

As a case study for initial cost problem, we realize new manipulation and perception for a heavy material handling agricultural robot with high-cost components reductions, which requires more robust controllers. A key point is a new combination of structure systems and control systems, not only one of the two. More precisely, first, we review and propose a new manipulator with a passive joint and a new camera configuration with only one camera. Second, we design robust controllers in gain-scheduling, μ-synthesis by using special characteristics of the robot in the presence of uncertainty, nonlinearity and constraint. Finally, we evaluate the validity by actual field experiments, which is the most important part of this paper. The manipulator and the camera configuration can not work well without the designed controllers. That is, the robust controllers reduce the initial cost.

View full abstract

This paper presents a controller design method of rudder angle servo systems for boats, which can utilize to obtain the maneuvering model of boats and to equip as one element of experimental setup for autopilot systems. A nonlinear feedback for hydraulic unit of rudder installation and the model following sliding mode control are applied to the proposed controller so as to show high robustness against the normal pressure of rudder, which changes according to navigation condition. As a means of reduction chattering due to the actuator dynamics, a switching input considered the characteristics of normal pressure is proposed. Finally, some numerical simulation results show the effectiveness of the proposed controller.

View full abstract

This paper discusses an application of sliding mode control theories to remote automatic operation of skid steer vehicle. Since it is very hard to control the angular velocity of the left-right wheel directly by an operator at middle or high speed, a virtual steer angle, which can be seen as the demanded proceeding direction of the vehicle, is introduced. Then, a desired stable model, which consists of a part of linearly approximated model of front wheel steer vehicle and a linearly approximated model of skid steer vehicle, is proposed as a reference model to be followed by the real vehicle. In order to achieve the desired dynamics robustly against disturbances or model uncertainties, a sliding mode controller is designed.

View full abstract

This paper discusses a control strategy for a mini helicopter having four rotors in planar motion. Based on the backstepping method employing the sliding mode theories together, a robust velocity-servo system is designed. Numerical simulation illustrates that a discontinuous moment input is very effective to eliminate the coupling between the rolling moment and the lateral acceleration of the helicopter.

View full abstract

This paper proposes an effective scheme for quick and precise tracking control of a piezoelectric actuator. The proposed approach is based on the combination of a feedforward loop and a PID(proportional integral derivative) feedback controller. The feedforward loop is formed by an inverse model of the actuator that includes hysteresis compensation, mechanical oscillations and losses compensation and resistive losses compensation. In order to avoid using a bulky and costly displacement sensor in the feedback loop, a detection model has been developed to compute the displacement of the piezoelectric actuator as a function of the supplying current.

View full abstract

In this paper, a sensing methodology is developed and experimentally investigated to detect and characterize damages, which are essentially accompanied by changes in the micro/macroscopic condition of surface contact. The proposed technique is developed mainly focusing on early detection of cracks in a beam structure, but also may be applicable to kissing bonds in adhesive joints as well as partial loss of preload in bolted joints under the operational condition. The presented system consists of PZT patches attached on the structural surface, one of which acts as a transmitter of high frequency harmonic wave. The incident harmonic wave is scattered by the contact surfaces which potentially involve damages, and received by the other patches. When the structure is subjected to the operational or ambient load at low frequencies, it vibrates, and the inherent damages may introduce a nonlinear effect to the vibro-acoustic dynamics that induces an interaction between the low frequency structural vibration and the high frequency transmitted wave. This nonlinearity is observed as the amplitude and phase modulation of the received wave due to the changes in the scattering characteristics synchronous with the structural vibration. By investigating the relationship between the modulations and the structural vibration, the nonlinear characteristics of the damages can be specified. Experiments using a beam with low-cycle fatigue cracks are conducted for illustrative purpose.

View full abstract

This paper deals with an integrated design of structural and control systems with a fault tolerant property. We obtain the optimal structural and control design parameters simultaneously by using a polynomial matrix approach. The polynomial matrix approach enables us to deal with a change of the closed-loop pole location in a case of a sensor and/or an actuator failure without substantial conservatism unlike traditional robust control approach based on Small gain paradigm. The condition where the closed-loop poles location remain in a specific region of the complex plane even in the sensor and/or the actuator fault is given as a simultaneous LMIs on the structural and the control design parameters. Those parameters are optimized simultaneously to optimize the property, e.g., energy for control, etc. while satisfying the fault tolerant property. With a design example we show the effectiveness of the present integrated design method.

View full abstract

A smart vortex generator(SVG) is proposed, which can be stowed during cruise to reduce drag. Posture of SVG can be transformed automatically by making SVG of a two-way-shape-memory(TWSM) alloy and using temperature difference between a cruise altitude and a low altitude. To investigate feasibility of SVG, a new TWSM model is proposed and a numerical simulation of motion of SVG is performed by using this proposed TWSM model and a finite element method. A result shows possibility of reciprocal motion of SVG between a vortex generating posture and a drag reducing posture by the temperature difference only.

View full abstract

This paper proposes a multidisciplinary design optimization approach of smart structures for sound suppression. The smart structure consists of panel with one fixed end, two piezoelectric ceramic actuators and control system. The control system is designed according to the H_2 specification with a reduced-order modal model derived from FEM and modal analysis. The sound pressure level of radiated sound from the vibrating panel is calculated by BEM. Derived sound pressure level is converted to loudness level according to ISO 226, and then radiated sound power level is calculated. The design problem for improving the H_2 performance is defined, and then the piezoelectric ceramic actuators and the control system are simultaneously optimized by the presented approach, resulting in an enhanced performance for the sound suppression.

View full abstract

This paper deals with motion and multi-modes vibration control of a flexible transportation system. In order to reduce a settling time from one position to another one, the vibration control is remarkably important on the transportation system. Since transportation system moves long distance, no limit in the measuring range of the sensor is required. For the purpose, piezoelectric films pasted on flexible structures are used as the point sensors to detect vibrations. To control the first two vibration modes, the reduced-order physical modeling method proposed by authors is applied and the control system is designed by LQ control approach. Control experiments demonstrate that the settling time is well shortened by controlling many-modes of vibration in addition to motion.

View full abstract

A new type taping for a vessel or piping is presented, in which water leakage is isolated automatically by its self-repairing mechanism against holes. The self-repairing unit (sealant layer) is consisting of three pieces of net with lattices inside. Polymer particles, which expand their volume with water is used for having self-repairing forces. In this sealant, water leaks along the boundary between the tape and the vessel. In order to retain the leak isolation force, this article first discusses a method for making the sealant tape, then develops a method for fixing the sealant to the vessel.

View full abstract

Smart structure systems have been expected to be develop as the practical application. The improvement of the social recognition for smart structure systems is an important subject, due to the concept of smart structure is not familiar in Japan. The teaching material is discussed in this paper, in order to enlighten the smart structure systems. This paper was considered the concept and validity of a proposed teaching material system, and was described the effectiveness of the teaching material for the smart structure system.

View full abstract

To obtaion imformation about temperature fluctuation to oparate the TiNi actuator, sensory evaluation tests for temperature fluctuation has been performed. At the leaved parts from the center of the body like finger tips of hand and foot, it was found to be able to endured the wider temperature fluctuation region at lower temperater from the temperature of body than that at higer temperature. In addition,at near parts the center of the body such as arm and leg, it became clear that there was no diffrence in the sensory evaluation value at high temperater and low temperartre compered with the temperature of body.

View full abstract

The measurement of the feeling of machine operation of power drill for architectural machine screw on the market have been performed. As a results,at the state of tunning off the power supply, the bad sense of grasping during handling existed in the part of the little finger and the palm of the hand. Morover, some machime caused a atrong pain on the palm and litlle finger after machine operation.Both of these penomena caused at the case of handle size came off the optimum grasping diameter.

View full abstract

This study investigated the evaluation of easiness to grasp the cylindrical objects of various diameters, and the movable angle at wrist joint movement and EMG activity of muscles in the forearm under the grasping. The optimum diameter of cylinder was found as 35mm under the condition of random order .Wrist joint movements of palmar-flexion, dorsi-flexion, ulnar-flexion and radial-flexion were investigated. The diameter of cylinder which produced maximum movable angle was 55mm in palmar-flexion, 60mm in dorsi-flexion, 55mm in ulnar-flexion and 20mm in radial-flexion, respectively. The mIEMG dose not change under 30 times repetition of the wrist joint movement.

View full abstract

This study investigated the evaluation of easiness to grasp badminton racket of various diameter, and the movable angle at wrist joint and EMG activity during racket swing motion. The wrist joint movement were palmar-flexion, dorsi- flexion,ulnar- flexion, and radial- flexion. EMG activity was measured for two minutes during ferformed and back swing altemation. The movable angle of palmar-flexion increased as the diameter above the optimum one. In the other movement the tendency was not found in the relationship between grip diameter and movable angle. EMG activity in grasping the optimum diameter of grip was reduction the passage of swing frequency compare with hardness grasping of grip. The decrease in the grip force after endurance swing motion grasping grip with optimum diameter was small.

View full abstract

We have performed basic experiments for the purpose of applying onomatopoeia to engineering problems. In these experiments, test subjects were made to perform lifting actions while listening to acoustic information. We tried to use onomatopoeic utterances and artificial sound as acoustic information. We thereby demonstrated that there is a relationship between the acoustic information and the lifting forces exerted by the test subjects. We investigated whether or not the artificial sound can substitute for the control by emotive and unemotive onomatopoeia.

View full abstract

This paper proposes to develop a golf club of a good hitting sound. The reliability of the result is confirmed by sensory evaluation to the hitting sound of the golf club by two methods. The feature of the method of sensory evaluation is understood from some difference points, and a suitable method for the evaluation of the hitting sound of the golf club is examined. Next, senses in the rating scale method are evaluated to some golf clubs that shapes are changed. As a result, it proposes the computational method of the sound quality evaluation parameter corresponding to the question item. The question item of the sensory evaluation questionnaire is examined. The difference of the evaluation by the presence of the golf experience is examined.

View full abstract

Use of a massage chair to relieve the muscle fatigue is useful also for the relief of a mental stress. The comfortableness improvement after the chair had been used was evaluated with physiological index. However, individual difference was shown and constant tendency of physiological response to the comfortable was not obtained. Then, thirty subjects were measured and their response was made the grope by the physiological index. As a result, it was clarified that the tendency to the rise of the skin temperature and the heart rate decrease became an evaluation index in the effect of the massage.

View full abstract

The purpose of this study is to reduce a transmission noise of floor structure by the active noise isolation unit which constructed from thin board and piezoelectric vibrator. The piezoelectric vibrator is attached to the thin board by the center connection bolt. Through the experiments, the effects of material of isolation control board on isolation characteristics were investigated. The experimental results show that isolation loss at input frequency from 120Hz to 500Hz is obtained about 30 to 60 dB by using thin and lightweight board. In addition, by using the insulator material pasted to the control board, the isolation loss could be increased.

View full abstract

This report describes an analysis of acoustic power radiated from the insulation panel system for reducing floor impact noise. The systems are comprised of actively controlled modular panels of light weight, which wholly cover the surface of concrete slab structure in the ceiling, and in each of which the mechanical vibration is controlled independently with moving coil actuators. In this report, the acoustic power is evaluated by the work done by normal velocity in the vibrating plate combining with the acoustic pressure expressed by the Rayleigh's formula. The analysis suggests the effectiveness of feed-back control system utilizing the vibration mode signals of the insulation panel. Among the bivration modes the most important is the one whose shape funtion is even about the center axes of the plate and results in the monopole sound radiation.

View full abstract

An acive sound absorbing device unit of the transmission noise through a wall, using a plate planewave speaker as the secondary sound source, was developed toward effective suppression of aircraft interior noise. The controller was designed using reference accelerometer attached on the wall, and based on the Filtered-x LMS algorithm, its system identification was in advance performed so as to minimize sound level at one observation point, and then act as an off-line controller. At first, control effects were estimated by the numerical analyses using the system model identified from the actual experimental devices. Then, active sound absorbing experiments were performed with band limited white noise applied to the unit, and it was shown that enough control effects were obtained at plural observation points located in three dimensional space.

View full abstract

We proposed the compact actuator system that aimed to increase the secondary sound source output of the active sound insulation cell. The active sound insulation cell that applied compact actuator system was manufactured for trial purposes. Internal sound field measurement and the active insulation examination of the cell were performed. And, the sound pressure level in the cell was measured, and the validity of the idea of the active sound insulation cell made for trial purposes was confirmed.

View full abstract

In the mechanical engineering field, a noise is often generated within the cabinet and propagates through the orifice and radiated to outer space. In that case, the sound propagates through both closed and open spaces. The finite difference method in time domain(FDTD) can be applied to closed space. In order to improve the accuracy of spatial differentiation, the compact finite differences were utilized in this report. As configurations of equipments can be well represeted by non-uniform grid, the compact finite difference on that grid was applied In the outer space, the sound field can be evaluated by the boundary integral calculation. The boundary values of the sound pressure and particle velocities in frequency domain were applied by the Fourier transformation of the results by FDTD. As an example. the sound pressure distributions around the equipment were evaluated The influences of the temperature change in the cabinet on the sound pressure were examined. Due to the discontinuity of the sound velocity and density at the opening, the reflection and refraction of sound wave at the orifice was predicted.

View full abstract

This paper numerically investigates the attenuation of global acoustic potential energy in a structural/acoustic coupled cavity using radiation cluster control. The rectangular enclosure considered here is composed of five rigid walls and a simply supported rectangular plate. Optimal feedforward control law to minimize the amplitudes of the radiation clusters is performed, and the control effect, the attenuation of the global acoustic potential energy, is calculated. It is found that radiation cluster control is a reasonable method to control sound radiation in a structural/acoustic coupled cavity based upon structural error sensing.

View full abstract

The purpose of this research is to reduce the floor impulse noise generated by heavy-weight impact source. The supporting leg with magnetic damper is designed to isolate the impact force from the double floor by magnetic surfacing. In the experiment, the performance of supporting leg with magnetic damper is evaluated from the static load, the impact load and the floor impulse noise. The experimental results show that the impact load could be reduced about 1/3 by using supporting leg with magnetic damper. And in the case of floor impulse experiment, the heavy-weight impact noise could be reduced about 8 to 11 dB.

View full abstract

This paper describes the statistical model of impact forces caused by coins falling to a storage box of a coin counter and the estimation of sound pressure radiated from the box. To represent the impulse of coin, the collision time and position of the impulse are defined as probability variables. Their probability density functions are assumed as Gaussian probability distribution. The measurement of vibration acceleration and radiated sound pressure in the initial excitation phase of coin is carried out. It is confirmed that the estimated frequency responses are coincided well with the measured values in low frequency domain.

View full abstract

Steel railway bridges characteristically tend to generate high-level structure-borne noise. The authors have developed a method to predict structure-borne noise, however it possesses a drawback that it is difficult to calculate directly the exciting force generated by train run. Considering that, in order to estimate the exciting force generated by train run, we exercised the following two types of tests in Hino civil engineering experimental field; one is an impact test and the other is a motorcar running test. As a result, it is revealed that as for the accelerance, which means a vibration acceleration divided by a load obtained by measuring the strain of web of rail, the values measured by the impact test is close to that by the motorcar running test in the range over 100Hz. From this result, it can be said that the exciting force generated by train run is able to be calculated by measuring or analyzing the vibration of rail.

View full abstract

In recent years, the rolling noises become an important problem of narrow-gauge vehicles.The noises are composed of rail noise and wheel one.As for rail noise,the characteristic of frequency are investigated by running test experimentally.However,the detail behavior does not become clear.Therefore, this paper reports the 3D characteristics of rail sound radiation obtained from FEM and BEM analysis comparing with result of narrow-gauge wheel analysis.We found that the main frequency of rail noise which occurred from bottom and flange part mainly,was 945Hz.The influences of sound reflection by slab plate are different from rail sound with wheel one.

View full abstract