Tsuyoshi Inoue | Nagoya University (original) (raw)

Papers by Tsuyoshi Inoue

Research paper thumbnail of Dynamic Analysis of Magnetically Levitated Conveyance System of a Rigid Body

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series C, 2005

Research paper thumbnail of Detection of a Rotor Crack by a Periodic Excitation

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series C, 2004

Research paper thumbnail of Formulation and experimental validation of a frequency transfer function of a rotor system with both an open crack and anisotropic support stiffness

Transactions of the JSME (in Japanese), 2018

This paper proposes a transfer function of rotating shaft system considering both an open crack a... more This paper proposes a transfer function of rotating shaft system considering both an open crack and anisotropy in bearing support stiffness, which are both fundamental characteristics often observed in the rotating machinery. Due to the interaction of anisotropy in bearing support and rotor crack, vibration component is generated without limitation. In this paper, the order of generated component is evaluated and a transfer function focusing on five vibration components is derived. Each transfer function is analyzed and characteristics of all resonances are explained theoretically. Then, the validity of this derived transfer function is confirmed by comparing with numerical simulation result. Furthermore, the experimental system of the rotating shaft supported by the bearing with anisotropic support stiffness is developed, and the harmonic excitation was added to this system by the active magnetic bearing. Several harmonic excitation experiments were carried out, and the resonances due to anisotropy in bearing support, rotor crack, and the interaction of anisotropy in bearing support and rotor crack were examined. The vibration characteristics of observed resonances showed quantitatively almost agreed results to the expected theoretical results. These theoretical and experimental results clarified the usefulness of the derived transfer function.

Research paper thumbnail of Nonlinear Vibration Analysis and Experiments of a Vertical Rigid Rotor-Magnetic Bearing System (Case Considering the Delay of Control Force)

Transactions of the Japan Society of Mechanical Engineers Series C, 2005

Research paper thumbnail of 1D-FEM Modeling of an Open Crack in a Rotor System and the Decision of It's Parameter Values (Derivation of the Governing Equations of Parameters Using 3D-FEM Software)

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series C, 2012

This paper investigates the concise 1D-FEM models of an open crack in a rotating shaft for quanti... more This paper investigates the concise 1D-FEM models of an open crack in a rotating shaft for quantitative analysis. The parameter of these models have been required to determine experimentally, which was the major drawback of these models. Therefore, in this paper, the decision procedures of the parameters in these models are discussed. The characteristics of the parameters regarding shaft's diameter and depth of crack are investigated by using numerical data obtained from 3D-FEM software. Then, the governing equation of the parameter for one model is deduced in terms of depth of crack. The validity of the decision procedure and the deduced governing equation of the model's parameter is clarified experimentally.

Research paper thumbnail of Modeling and Dynamical Analysis of a Gyroscopic Exercise Tool Considering Both Collision and Slide between the Rotor and Case

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series C, 2012

Research paper thumbnail of Vibration of Translation-Inclination Coupled System Under the Periodic Base Motion (Auto-parametric Resonance, and Influences of Height of Center of Mass, Imbalance of Mass and Difference of Stiffness)

Transactions of the Japan Society of Mechanical Engineers Series C, 2006

Research paper thumbnail of Nonlinear Analysis of a Torsional Vibration of a Rotor with Centrifugal Pendulum Vibration Absorbers and Its Suppression

Transactions of the Japan Society of Mechanical Engineers Series C, 2005

Research paper thumbnail of Vibration of a Vertical Rigid Rotor Supported by a Repulsive Magnetic Bearing (Influences of Magnetical Anisotropicities of Inner and Outer Magnets)

Transactions of the Japan Society of Mechanical Engineers Series C, 2006

Research paper thumbnail of Finite Element Analysis of the Vibration of a Rotor System with an Open Crack under the Harmonic Excitation

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series C, 2013

This paper develops an analytical method of the vibration of the finite element rotating shaft mo... more This paper develops an analytical method of the vibration of the finite element rotating shaft model with an open crack which was developed in our previous study. Particularly, the vibration of the rotating shaft with an open crack under the harmonic excitation is investigated, and the fundamental equations governing the vibration of the cracked shaft are derived in that case. By comparing the obtained their theoretical results with the experimental results quantitatively, the validity of the analytical methods and the derived fundamental equations are verified. This result contributes to detect a crack of a rotor in its early stage.

Research paper thumbnail of Nonlinear Modeling and Parameter Estimation of the Magnetic Levitation System Considering the Dynamics of the Control System (Case with Approximating the Electric Circuit and Magnetic Circuit Independently )

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series C, 2011

The magnetic levitation system has not only the strong nonlinearity in the magnetic force but als... more The magnetic levitation system has not only the strong nonlinearity in the magnetic force but also the delays in electric circuit and magnetic circuit. This paper investigates the modeling of the magnetically levitated body considering both of them. The dynamic coefficients of the electric circuit and magnetic circuit of control system are estimated independently by using the transfer function. The model and estimated parameter values are validated experimentally by comparing the resonance curves of numerical simulation and experiment.

Research paper thumbnail of Finite Element Vibration Analysis of a Rotor System with an Open Crack (Analysis of Natural Frequency and Double Frequency Vibration in the Case with the Asymmetric Support Stiffness Characteristics)

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series C, 2012

This paper develops an analytical method of the vibration of the finite element rotating shaft mo... more This paper develops an analytical method of the vibration of the finite element rotating shaft model with an open crack which was developed in our previous study. Particularly, the case with the directional difference of the bearing support stiffness is focused, and the analytical methods of the natural frequency and the double frequency vibration due to open crack are developed with introducing the order evaluation. By comparing the obtained their theoretical results with the experimental results quantitatively, the validity of the analytical methods is verified. As a result, the theoretical analysis of vibration characteristic of the rotor system with an open crack becomes available regardless of the existence of directional difference of the bearing support stiffness, and it contributes to detect a crack of a rotor in its early stage.

Research paper thumbnail of Nonlinear Restoring Force Characteristic and Vibration of a Rotating Shaft Supported by a Repulsive Magnetic Bearing (Influences of Both the Axial Displacement and the Magnetic Length Ratio)

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series C, 2011

Research paper thumbnail of Nonlinear Vibration Analysis of a Flexible Rotor Supported by the Full-Circular Journal Bearing (Numerical Analysis Using the Shooting Method under the Half Sommerfeld Boundary Condition)

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series C, 2013

This study investigates the nonlinear vibration of the flexible rotor supported by the full-circu... more This study investigates the nonlinear vibration of the flexible rotor supported by the full-circular journal bearing. The numerical simulation method, so called shooting method, is utilized to investigate both stable and unstable solutions. Both the synchronous and asynchronous vibrations are analyzed. Because the shooting method is available only for the periodic solution, the investigation of the asynchronous vibration is performed only for the case without unbalance of the rotor system. The dynamical characteristics of the asynchronous vibration, such as its occurrence range and shape of branches including stable and unstable solutions, are clarified. Also, the influences of viscosity and stiffness ratio between the shaft and bearing on the dynamical characteristics of the asynchronous vibration are explained.

Research paper thumbnail of Rolling contact whirling motion of a rotating shaft supported by a repulsive magnetic bearing and a rotatable backup bearing (Influences of friction coefficient and damping)

Transactions of the JSME (in Japanese), 2014

Research paper thumbnail of 水平支持されたジェフコットロータにおける主共振の非線形特性

Transactions of the Japan Society of Mechanical Engineers Series C, 2008

Research paper thumbnail of FEM Modelling and Experimental Verification of a Rotor System With a Open Crack

Volume 1: 22nd Biennial Conference on Mechanical Vibration and Noise, Parts A and B, 2009

ABSTRACT

Research paper thumbnail of Some Observations of Mode Localizations in Flexibly Coupled Two Rotors

Volume 1: 20th Biennial Conference on Mechanical Vibration and Noise, Parts A, B, and C, 2005

Rotating machineries are one of the most widely used elements in mechanical systems. Objective of... more Rotating machineries are one of the most widely used elements in mechanical systems. Objective of this research is to investigate some nonlinear phenomena in rotor systems. First, we propose a general method to theoretically analyze nonlinear phenomena. The averaged equations for the complex amplitudes of the forward and backward whirling motions are derived in order to perform bifurcation analysis. We focus on the motion of a horizontally supported single-span rotor and theoretically and experimentally clarify that the cubic and quintic nonlinearities take important role for the nonlinear dynamics of the system. Furthermore, it is theoretically and experimentally shown that this system exhibits hardening and softening types responses depending on the rotational speed, due to the effects of gravity and nonlinear characteristics of the rotor. Next, we consider multiple-span rotors. Mode localizations in a weakly coupled two-span rotor system are theoretically investigated. One rotor has a slight unbalance and the other one is well-assembled. First, the equations governing the whirling motions of the coupled rotors are derived by taking into account nonlinearity in each span and weakness of the coupling between them. The averaged equations indicate that the nonlinear normal modes are bifurcated from the linear normal modes. Also, it is theoretically clarified that whirling motion caused by the unbalance in the rotor is localized

Research paper thumbnail of Sensor-less parameter estimation of electromagnetic transducer and experimental verification

Active and Passive Smart Structures and Integrated Systems 2015, 2015

In this paper, a new sensor-less parameter estimation method is proposed for electromagnetic shun... more In this paper, a new sensor-less parameter estimation method is proposed for electromagnetic shunt damping. The purpose is to estimate parameters of an electromagnetic transducer and a vibrating structure. The frequency domain measurements of an electrical admittance are only supposed to be available but any other sensor measurements are not; therefore, the estimation problem is nontrivial. Two types of numerical optimization, a linear optimization to select an initial seed and a nonlinear optimization to determine a final estimate, are presented. The effectiveness of the method is demonstrated by vibration control experiments as well as parameter estimation experiments.

Research paper thumbnail of Vibration Control and Unbalance Estimation of a Nonlinear Rotor System Using Disturbance Observer

Journal of Vibration and Acoustics, 2009

In rotating machinery, rotor unbalance causes many resonances at critical speeds corresponding to... more In rotating machinery, rotor unbalance causes many resonances at critical speeds corresponding to different modes. In this paper, a vibration control method for rotor systems utilizing disturbance observer is proposed. The nonlinear terms, unbalance, parameter variations, and uncertain terms of a rotor system are lumped into a disturbance term, and this term is canceled by using disturbance observer. As a result, the vibrations are suppressed to small amplitudes all over the rotational speed range. Simultaneously, unbalance of the first mode is estimated from the information of control force of disturbance observer. Moreover, the effects of parameter errors of the control system are also investigated. The validity of the proposed method is verified through numerical simulations and experiments.

Research paper thumbnail of Dynamic Analysis of Magnetically Levitated Conveyance System of a Rigid Body

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series C, 2005

Research paper thumbnail of Detection of a Rotor Crack by a Periodic Excitation

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series C, 2004

Research paper thumbnail of Formulation and experimental validation of a frequency transfer function of a rotor system with both an open crack and anisotropic support stiffness

Transactions of the JSME (in Japanese), 2018

This paper proposes a transfer function of rotating shaft system considering both an open crack a... more This paper proposes a transfer function of rotating shaft system considering both an open crack and anisotropy in bearing support stiffness, which are both fundamental characteristics often observed in the rotating machinery. Due to the interaction of anisotropy in bearing support and rotor crack, vibration component is generated without limitation. In this paper, the order of generated component is evaluated and a transfer function focusing on five vibration components is derived. Each transfer function is analyzed and characteristics of all resonances are explained theoretically. Then, the validity of this derived transfer function is confirmed by comparing with numerical simulation result. Furthermore, the experimental system of the rotating shaft supported by the bearing with anisotropic support stiffness is developed, and the harmonic excitation was added to this system by the active magnetic bearing. Several harmonic excitation experiments were carried out, and the resonances due to anisotropy in bearing support, rotor crack, and the interaction of anisotropy in bearing support and rotor crack were examined. The vibration characteristics of observed resonances showed quantitatively almost agreed results to the expected theoretical results. These theoretical and experimental results clarified the usefulness of the derived transfer function.

Research paper thumbnail of Nonlinear Vibration Analysis and Experiments of a Vertical Rigid Rotor-Magnetic Bearing System (Case Considering the Delay of Control Force)

Transactions of the Japan Society of Mechanical Engineers Series C, 2005

Research paper thumbnail of 1D-FEM Modeling of an Open Crack in a Rotor System and the Decision of It's Parameter Values (Derivation of the Governing Equations of Parameters Using 3D-FEM Software)

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series C, 2012

This paper investigates the concise 1D-FEM models of an open crack in a rotating shaft for quanti... more This paper investigates the concise 1D-FEM models of an open crack in a rotating shaft for quantitative analysis. The parameter of these models have been required to determine experimentally, which was the major drawback of these models. Therefore, in this paper, the decision procedures of the parameters in these models are discussed. The characteristics of the parameters regarding shaft's diameter and depth of crack are investigated by using numerical data obtained from 3D-FEM software. Then, the governing equation of the parameter for one model is deduced in terms of depth of crack. The validity of the decision procedure and the deduced governing equation of the model's parameter is clarified experimentally.

Research paper thumbnail of Modeling and Dynamical Analysis of a Gyroscopic Exercise Tool Considering Both Collision and Slide between the Rotor and Case

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series C, 2012

Research paper thumbnail of Vibration of Translation-Inclination Coupled System Under the Periodic Base Motion (Auto-parametric Resonance, and Influences of Height of Center of Mass, Imbalance of Mass and Difference of Stiffness)

Transactions of the Japan Society of Mechanical Engineers Series C, 2006

Research paper thumbnail of Nonlinear Analysis of a Torsional Vibration of a Rotor with Centrifugal Pendulum Vibration Absorbers and Its Suppression

Transactions of the Japan Society of Mechanical Engineers Series C, 2005

Research paper thumbnail of Vibration of a Vertical Rigid Rotor Supported by a Repulsive Magnetic Bearing (Influences of Magnetical Anisotropicities of Inner and Outer Magnets)

Transactions of the Japan Society of Mechanical Engineers Series C, 2006

Research paper thumbnail of Finite Element Analysis of the Vibration of a Rotor System with an Open Crack under the Harmonic Excitation

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series C, 2013

This paper develops an analytical method of the vibration of the finite element rotating shaft mo... more This paper develops an analytical method of the vibration of the finite element rotating shaft model with an open crack which was developed in our previous study. Particularly, the vibration of the rotating shaft with an open crack under the harmonic excitation is investigated, and the fundamental equations governing the vibration of the cracked shaft are derived in that case. By comparing the obtained their theoretical results with the experimental results quantitatively, the validity of the analytical methods and the derived fundamental equations are verified. This result contributes to detect a crack of a rotor in its early stage.

Research paper thumbnail of Nonlinear Modeling and Parameter Estimation of the Magnetic Levitation System Considering the Dynamics of the Control System (Case with Approximating the Electric Circuit and Magnetic Circuit Independently )

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series C, 2011

The magnetic levitation system has not only the strong nonlinearity in the magnetic force but als... more The magnetic levitation system has not only the strong nonlinearity in the magnetic force but also the delays in electric circuit and magnetic circuit. This paper investigates the modeling of the magnetically levitated body considering both of them. The dynamic coefficients of the electric circuit and magnetic circuit of control system are estimated independently by using the transfer function. The model and estimated parameter values are validated experimentally by comparing the resonance curves of numerical simulation and experiment.

Research paper thumbnail of Finite Element Vibration Analysis of a Rotor System with an Open Crack (Analysis of Natural Frequency and Double Frequency Vibration in the Case with the Asymmetric Support Stiffness Characteristics)

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series C, 2012

This paper develops an analytical method of the vibration of the finite element rotating shaft mo... more This paper develops an analytical method of the vibration of the finite element rotating shaft model with an open crack which was developed in our previous study. Particularly, the case with the directional difference of the bearing support stiffness is focused, and the analytical methods of the natural frequency and the double frequency vibration due to open crack are developed with introducing the order evaluation. By comparing the obtained their theoretical results with the experimental results quantitatively, the validity of the analytical methods is verified. As a result, the theoretical analysis of vibration characteristic of the rotor system with an open crack becomes available regardless of the existence of directional difference of the bearing support stiffness, and it contributes to detect a crack of a rotor in its early stage.

Research paper thumbnail of Nonlinear Restoring Force Characteristic and Vibration of a Rotating Shaft Supported by a Repulsive Magnetic Bearing (Influences of Both the Axial Displacement and the Magnetic Length Ratio)

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series C, 2011

Research paper thumbnail of Nonlinear Vibration Analysis of a Flexible Rotor Supported by the Full-Circular Journal Bearing (Numerical Analysis Using the Shooting Method under the Half Sommerfeld Boundary Condition)

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series C, 2013

This study investigates the nonlinear vibration of the flexible rotor supported by the full-circu... more This study investigates the nonlinear vibration of the flexible rotor supported by the full-circular journal bearing. The numerical simulation method, so called shooting method, is utilized to investigate both stable and unstable solutions. Both the synchronous and asynchronous vibrations are analyzed. Because the shooting method is available only for the periodic solution, the investigation of the asynchronous vibration is performed only for the case without unbalance of the rotor system. The dynamical characteristics of the asynchronous vibration, such as its occurrence range and shape of branches including stable and unstable solutions, are clarified. Also, the influences of viscosity and stiffness ratio between the shaft and bearing on the dynamical characteristics of the asynchronous vibration are explained.

Research paper thumbnail of Rolling contact whirling motion of a rotating shaft supported by a repulsive magnetic bearing and a rotatable backup bearing (Influences of friction coefficient and damping)

Transactions of the JSME (in Japanese), 2014

Research paper thumbnail of 水平支持されたジェフコットロータにおける主共振の非線形特性

Transactions of the Japan Society of Mechanical Engineers Series C, 2008

Research paper thumbnail of FEM Modelling and Experimental Verification of a Rotor System With a Open Crack

Volume 1: 22nd Biennial Conference on Mechanical Vibration and Noise, Parts A and B, 2009

ABSTRACT

Research paper thumbnail of Some Observations of Mode Localizations in Flexibly Coupled Two Rotors

Volume 1: 20th Biennial Conference on Mechanical Vibration and Noise, Parts A, B, and C, 2005

Rotating machineries are one of the most widely used elements in mechanical systems. Objective of... more Rotating machineries are one of the most widely used elements in mechanical systems. Objective of this research is to investigate some nonlinear phenomena in rotor systems. First, we propose a general method to theoretically analyze nonlinear phenomena. The averaged equations for the complex amplitudes of the forward and backward whirling motions are derived in order to perform bifurcation analysis. We focus on the motion of a horizontally supported single-span rotor and theoretically and experimentally clarify that the cubic and quintic nonlinearities take important role for the nonlinear dynamics of the system. Furthermore, it is theoretically and experimentally shown that this system exhibits hardening and softening types responses depending on the rotational speed, due to the effects of gravity and nonlinear characteristics of the rotor. Next, we consider multiple-span rotors. Mode localizations in a weakly coupled two-span rotor system are theoretically investigated. One rotor has a slight unbalance and the other one is well-assembled. First, the equations governing the whirling motions of the coupled rotors are derived by taking into account nonlinearity in each span and weakness of the coupling between them. The averaged equations indicate that the nonlinear normal modes are bifurcated from the linear normal modes. Also, it is theoretically clarified that whirling motion caused by the unbalance in the rotor is localized

Research paper thumbnail of Sensor-less parameter estimation of electromagnetic transducer and experimental verification

Active and Passive Smart Structures and Integrated Systems 2015, 2015

In this paper, a new sensor-less parameter estimation method is proposed for electromagnetic shun... more In this paper, a new sensor-less parameter estimation method is proposed for electromagnetic shunt damping. The purpose is to estimate parameters of an electromagnetic transducer and a vibrating structure. The frequency domain measurements of an electrical admittance are only supposed to be available but any other sensor measurements are not; therefore, the estimation problem is nontrivial. Two types of numerical optimization, a linear optimization to select an initial seed and a nonlinear optimization to determine a final estimate, are presented. The effectiveness of the method is demonstrated by vibration control experiments as well as parameter estimation experiments.

Research paper thumbnail of Vibration Control and Unbalance Estimation of a Nonlinear Rotor System Using Disturbance Observer

Journal of Vibration and Acoustics, 2009

In rotating machinery, rotor unbalance causes many resonances at critical speeds corresponding to... more In rotating machinery, rotor unbalance causes many resonances at critical speeds corresponding to different modes. In this paper, a vibration control method for rotor systems utilizing disturbance observer is proposed. The nonlinear terms, unbalance, parameter variations, and uncertain terms of a rotor system are lumped into a disturbance term, and this term is canceled by using disturbance observer. As a result, the vibrations are suppressed to small amplitudes all over the rotational speed range. Simultaneously, unbalance of the first mode is estimated from the information of control force of disturbance observer. Moreover, the effects of parameter errors of the control system are also investigated. The validity of the proposed method is verified through numerical simulations and experiments.