The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform

Takehiko Asai - One of the best experts on this subject based on the ideXlab platform.

  • Enhanced power absorption of a point absorber wave energy converter using a tuned Inertial Mass
    Energy, 2020
    Co-Authors: Ruriko Haraguchi, Takehiko Asai
    Abstract:

    Abstract A novel point absorber wave energy converter with a tuned Inertial Mass (TIM), which is capable of significantly increasing the energy absorption and broadening the effective bandwidth, is proposed in this paper. The mechanism of the TIM has originally been introduced in the field of civil engineering as a passive energy absorber for structures subjected to external loadings such as earthquakes. It relies on attaching an additional tuning spring and a rotational Inertial Mass to the primary system, to improve the energy absorption performance by amplifying the displacement of the damper. Thus, considering typical point absorbers modeled as a Mass-spring-dashpot system similar way to civil structures, the application of the TIM to wave energy converters can be expected to have a significant effect. In this paper, numerical investigation on the power generation performance of a point absorber with the TIM is conducted under random sea waves. The amplitude response and power generation performance are compared with the conventional point absorber, considering both non-resonant and resonant buoy cases. It is shown that by properly designing the tuning spring stiffness and generator damping, the rotation of the generator can be amplified compared to the buoy, increasing the power absorption drastically.

  • Experimental verification of a tuned Inertial Mass electromagnetic transducer
    Active and Passive Smart Structures and Integrated Systems XII, 2018
    Co-Authors: Y. Watanabe, K. Sugiura, Takehiko Asai
    Abstract:

    This research reports on the design and experimental verification of a tuned Inertial Mass electromagnetic trans- ducer (TIMET) for energy harvesting from vibrating large structures and structural vibration control devices. The TIMET consists of a permanent-magnetic synchronous motor (PMSM), a rotational Mass, and a tuning spring. The PMSM and the rotational Mass are connected to a ball screw mechanism so that the rotation of the PMSM is synchronized with the rotational Mass. And the tuning spring interfaced to the shaft of the ball screw mechanism is connected to the vibrating structure. Thus, through this ball screw mechanism, transla- tional vibration motion of the structure is converted to rotational behavior and mechanical energy is absorbed as electrical energy by the PMSM. Moreover, the amplified equivalent Inertial Mass effect is obtained by rotating relatively small physical Masses. Therefore, when the stiffness of the tuning spring is determined so that the Inertial Mass resonates with the natural frequency of the vibratory structure, the PMSM rotates more effectively. As a result, the generated energy by the PMSM can be increased. The authors design a prototype of the TIMET and carry out experiments using sine and sine seep waves to show the effectiveness of the tuned Inertial Mass mechanism. Also, an analytical model of the proposed device is developed using a curve fitting technique to simulate the behavior of the TIMET.

  • structural control with tuned Inertial Mass electromagnetic transducers
    Structural Control & Health Monitoring, 2018
    Co-Authors: Takehiko Asai, Yoshikazu Araki, Kohju Ikago
    Abstract:

    Summary This paper investigates the validity of the tuned Inertial Mass electromagnetic transducer (TIMET) applied to building structures subjected to seismic motions. The TIMET is a device inspired by two innovative structural control devices proposed recently, that is, tuned viscous Mass damper and electromagnetic transducer. The TIMET consists of a spring, an Inertial Mass produced by a ball screw mechanism, and an electromagnetic transducer part composed of a motor and an electrical circuit. The stiffness of the spring is tuned such that the Inertial Mass resonates with the vibrating building. This makes the motor installed in parallel with the Inertial Mass run up in an efficient way, and the vibration energy is converted to electrical energy effectively. As a result, vibration of the building decays fast and electrical energy is stored. This generated energy that is reusable for the self-powered control systems, structural health monitoring, emergency power source, and so on. In this paper, through numerical simulation studies employing the scaled three-story building model proposed for benchmark studies, the vibration reduction and energy harvesting capabilities of the TIMET is explored and the application potentiality to civil structures is discussed.

  • Experimental verification of a tuned Inertial Mass electromagnetic transducer
    Proceedings of SPIE - The International Society for Optical Engineering, 2018
    Co-Authors: Y. Watanabe, K. Sugiura, Takehiko Asai
    Abstract:

    © 2018 SPIE. This research reports on the design and experimental verification of a tuned Inertial Mass electromagnetic trans- ducer (TIMET) for energy harvesting from vibrating large structures and structural vibration control devices. The TIMET consists of a permanent-magnetic synchronous motor (PMSM), a rotational Mass, and a tuning spring. The PMSM and the rotational Mass are connected to a ball screw mechanism so that the rotation of the PMSM is synchronized with the rotational Mass. And the tuning spring interfaced to the shaft of the ball screw mechanism is connected to the vibrating structure. Thus, through this ball screw mechanism, transla- tional vibration motion of the structure is converted to rotational behavior and mechanical energy is absorbed as electrical energy by the PMSM. Moreover, the amplified equivalent Inertial Mass ect is obtained by rotating relatively small physical Masses. Therefore, when the stiness of the tuning spring is determined so that the Inertial Mass resonates with the natural frequency of the vibratory structure, the PMSM rotates more ectively. As a result, the generated energy by the PMSM can be increased. The authors design a prototype of the TIMET and carry out experiments using sine and sine seep waves to show the ectiveness of the tuned Inertial Mass mechanism. Also, an analytical model of the proposed device is developed using a curve fitting technique to simulate the behavior of the TIMET.

  • outrigger tuned Inertial Mass electromagnetic transducers for high rise buildings subject to long period earthquakes
    Engineering Structures, 2017
    Co-Authors: Takehiko Asai, Y. Watanabe
    Abstract:

    Abstract This paper proposes outrigger tuned Inertial Mass electromagnetic transducer (TIMET) systems for high-rise buildings subject to long period earthquake excitations. The proposed outrigger TIMET systems consist of the outrigger and TIMET parts. The outrigger damping systems have been proposed as a novel energy dissipation approach to high-rise buildings, in which control devices are installed vertically between the outrigger and perimeter columns to achieve large energy dissipation. While the TIMET has been developed based on the mechanism of the tuned viscous Mass damper (TVMD) which can improve energy absorbing capability by taking advantage of resonance effect. However, instead of a viscous material, the damping of the TIMET is provided by a motor which can convert mechanical energy to electrical energy. The focus of this study is to investigate the structural control performance and energy harvesting efficiency of the proposed outrigger TIMET system for high-rise buildings subjected to long period earthquakes through numerical simulations.

Kohju Ikago - One of the best experts on this subject based on the ideXlab platform.

  • structural control with tuned Inertial Mass electromagnetic transducers
    Structural Control & Health Monitoring, 2018
    Co-Authors: Takehiko Asai, Yoshikazu Araki, Kohju Ikago
    Abstract:

    Summary This paper investigates the validity of the tuned Inertial Mass electromagnetic transducer (TIMET) applied to building structures subjected to seismic motions. The TIMET is a device inspired by two innovative structural control devices proposed recently, that is, tuned viscous Mass damper and electromagnetic transducer. The TIMET consists of a spring, an Inertial Mass produced by a ball screw mechanism, and an electromagnetic transducer part composed of a motor and an electrical circuit. The stiffness of the spring is tuned such that the Inertial Mass resonates with the vibrating building. This makes the motor installed in parallel with the Inertial Mass run up in an efficient way, and the vibration energy is converted to electrical energy effectively. As a result, vibration of the building decays fast and electrical energy is stored. This generated energy that is reusable for the self-powered control systems, structural health monitoring, emergency power source, and so on. In this paper, through numerical simulation studies employing the scaled three-story building model proposed for benchmark studies, the vibration reduction and energy harvesting capabilities of the TIMET is explored and the application potentiality to civil structures is discussed.

  • Energy harvesting potential of tuned Inertial Mass electromagnetic transducers
    Mechanical Systems and Signal Processing, 2017
    Co-Authors: Takehiko Asai, Yoshikazu Araki, Kohju Ikago
    Abstract:

    The demand for developing renewable energy technologies has been growing in today's society. As one of promising renewable energy sources, large-scale energy harvesting from structural vibrations employing electromagnetic transducers has recently been proposed and considerable effort has been devoted to increase the power generation capability. In this paper, we introduce the mechanism of a tuned Inertial Mass electromagnetic transducer (TIMET), which can absorb vibratory energy more efficiently by tuning the parameters to adjust the system. Then we propose a new vibratory energy harvester with the TIMET and determine the parameter values for the device with a simple static admittance (SA) control law to maximize the energy harvested from a stationary stochastic disturbance. To investigate the energy harvesting potential of the TIMET further, the performance-guaranteed (PG) control and the LQG control proposed in the literature are applied as well. Then the numerical simulation studies are carried out and the effectiveness of the proposed energy harvester is examined by comparing the traditional electromagnetic transducers.

Yoshikazu Araki - One of the best experts on this subject based on the ideXlab platform.

  • structural control with tuned Inertial Mass electromagnetic transducers
    Structural Control & Health Monitoring, 2018
    Co-Authors: Takehiko Asai, Yoshikazu Araki, Kohju Ikago
    Abstract:

    Summary This paper investigates the validity of the tuned Inertial Mass electromagnetic transducer (TIMET) applied to building structures subjected to seismic motions. The TIMET is a device inspired by two innovative structural control devices proposed recently, that is, tuned viscous Mass damper and electromagnetic transducer. The TIMET consists of a spring, an Inertial Mass produced by a ball screw mechanism, and an electromagnetic transducer part composed of a motor and an electrical circuit. The stiffness of the spring is tuned such that the Inertial Mass resonates with the vibrating building. This makes the motor installed in parallel with the Inertial Mass run up in an efficient way, and the vibration energy is converted to electrical energy effectively. As a result, vibration of the building decays fast and electrical energy is stored. This generated energy that is reusable for the self-powered control systems, structural health monitoring, emergency power source, and so on. In this paper, through numerical simulation studies employing the scaled three-story building model proposed for benchmark studies, the vibration reduction and energy harvesting capabilities of the TIMET is explored and the application potentiality to civil structures is discussed.

  • Energy harvesting potential of tuned Inertial Mass electromagnetic transducers
    Mechanical Systems and Signal Processing, 2017
    Co-Authors: Takehiko Asai, Yoshikazu Araki, Kohju Ikago
    Abstract:

    The demand for developing renewable energy technologies has been growing in today's society. As one of promising renewable energy sources, large-scale energy harvesting from structural vibrations employing electromagnetic transducers has recently been proposed and considerable effort has been devoted to increase the power generation capability. In this paper, we introduce the mechanism of a tuned Inertial Mass electromagnetic transducer (TIMET), which can absorb vibratory energy more efficiently by tuning the parameters to adjust the system. Then we propose a new vibratory energy harvester with the TIMET and determine the parameter values for the device with a simple static admittance (SA) control law to maximize the energy harvested from a stationary stochastic disturbance. To investigate the energy harvesting potential of the TIMET further, the performance-guaranteed (PG) control and the LQG control proposed in the literature are applied as well. Then the numerical simulation studies are carried out and the effectiveness of the proposed energy harvester is examined by comparing the traditional electromagnetic transducers.

Y. Watanabe - One of the best experts on this subject based on the ideXlab platform.

  • Experimental verification of a tuned Inertial Mass electromagnetic transducer
    Active and Passive Smart Structures and Integrated Systems XII, 2018
    Co-Authors: Y. Watanabe, K. Sugiura, Takehiko Asai
    Abstract:

    This research reports on the design and experimental verification of a tuned Inertial Mass electromagnetic trans- ducer (TIMET) for energy harvesting from vibrating large structures and structural vibration control devices. The TIMET consists of a permanent-magnetic synchronous motor (PMSM), a rotational Mass, and a tuning spring. The PMSM and the rotational Mass are connected to a ball screw mechanism so that the rotation of the PMSM is synchronized with the rotational Mass. And the tuning spring interfaced to the shaft of the ball screw mechanism is connected to the vibrating structure. Thus, through this ball screw mechanism, transla- tional vibration motion of the structure is converted to rotational behavior and mechanical energy is absorbed as electrical energy by the PMSM. Moreover, the amplified equivalent Inertial Mass effect is obtained by rotating relatively small physical Masses. Therefore, when the stiffness of the tuning spring is determined so that the Inertial Mass resonates with the natural frequency of the vibratory structure, the PMSM rotates more effectively. As a result, the generated energy by the PMSM can be increased. The authors design a prototype of the TIMET and carry out experiments using sine and sine seep waves to show the effectiveness of the tuned Inertial Mass mechanism. Also, an analytical model of the proposed device is developed using a curve fitting technique to simulate the behavior of the TIMET.

  • Experimental verification of a tuned Inertial Mass electromagnetic transducer
    Proceedings of SPIE - The International Society for Optical Engineering, 2018
    Co-Authors: Y. Watanabe, K. Sugiura, Takehiko Asai
    Abstract:

    © 2018 SPIE. This research reports on the design and experimental verification of a tuned Inertial Mass electromagnetic trans- ducer (TIMET) for energy harvesting from vibrating large structures and structural vibration control devices. The TIMET consists of a permanent-magnetic synchronous motor (PMSM), a rotational Mass, and a tuning spring. The PMSM and the rotational Mass are connected to a ball screw mechanism so that the rotation of the PMSM is synchronized with the rotational Mass. And the tuning spring interfaced to the shaft of the ball screw mechanism is connected to the vibrating structure. Thus, through this ball screw mechanism, transla- tional vibration motion of the structure is converted to rotational behavior and mechanical energy is absorbed as electrical energy by the PMSM. Moreover, the amplified equivalent Inertial Mass ect is obtained by rotating relatively small physical Masses. Therefore, when the stiness of the tuning spring is determined so that the Inertial Mass resonates with the natural frequency of the vibratory structure, the PMSM rotates more ectively. As a result, the generated energy by the PMSM can be increased. The authors design a prototype of the TIMET and carry out experiments using sine and sine seep waves to show the ectiveness of the tuned Inertial Mass mechanism. Also, an analytical model of the proposed device is developed using a curve fitting technique to simulate the behavior of the TIMET.

  • outrigger tuned Inertial Mass electromagnetic transducers for high rise buildings subject to long period earthquakes
    Engineering Structures, 2017
    Co-Authors: Takehiko Asai, Y. Watanabe
    Abstract:

    Abstract This paper proposes outrigger tuned Inertial Mass electromagnetic transducer (TIMET) systems for high-rise buildings subject to long period earthquake excitations. The proposed outrigger TIMET systems consist of the outrigger and TIMET parts. The outrigger damping systems have been proposed as a novel energy dissipation approach to high-rise buildings, in which control devices are installed vertically between the outrigger and perimeter columns to achieve large energy dissipation. While the TIMET has been developed based on the mechanism of the tuned viscous Mass damper (TVMD) which can improve energy absorbing capability by taking advantage of resonance effect. However, instead of a viscous material, the damping of the TIMET is provided by a motor which can convert mechanical energy to electrical energy. The focus of this study is to investigate the structural control performance and energy harvesting efficiency of the proposed outrigger TIMET system for high-rise buildings subjected to long period earthquakes through numerical simulations.

Wenai Shen - One of the best experts on this subject based on the ideXlab platform.

  • mechanical and energy harvesting model for electromagnetic Inertial Mass dampers
    Mechanical Systems and Signal Processing, 2019
    Co-Authors: Yamin Li, Wenai Shen
    Abstract:

    Abstract Recently, a novel inerter-based damper termed electromagnetic Inertial Mass damper (EIMD) that is capable of generating a large inertance and providing a controllable electromagnetic (EM) damping has been used as an energy dissipation device for seismic response control. Structural vibration energy induced by external loading is converted into electricity via the EIMD, for being dissipated and harvested. In this paper, the EIMD is proposed for simultaneous vibration mitigation and energy harvesting for the first time. A new mechanical model is proposed to predict the nonlinear behavior of the EIMD, and a linearized model is subsequently deduced based on the equal energy dissipation rule. In addition, an energy-harvesting model is presented to predict the output power and energy harvesting efficiency of the EIMD. To maximize the efficiency of the EIMD, this paper derives the corresponding optimal load resistance that can serve as the design criteria for an energy harvesting circuit (EHC). The proposed models are validated by the dynamic test of a prototype EIMD using harmonic excitation.