Sanwa Tekki Corporation

Tokyo, Japan

Sanwa Tekki Corporation

Tokyo, Japan
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Hiramoto K.,Niigata University | Matsuoka T.,Meiji University | Sunakoda K.,Sanwa Tekki Corporation
Structural Control and Health Monitoring | Year: 2016

Summary A new semi-active control strategy that approximates a predicted control output of a reference active control is proposed. A variable parameter of a semi-active control device is selected at every time instant so that the predicted control output of the semi-active control system becomes close to the corresponding predicted control output of the reference active control as much as possible. Parameters of the reference active control law are optimized in the premise of the aforementioned 'output emulation' strategy so that the control performance of the semi-active control becomes good and the 'error' in the sense of achieved control performance between the reference active control and semi-active control systems becomes small. A pole placement method based on a linear matrix inequality (LMI) framework is adopted as the reference active control law. Parameters to determine the domain in the complex plane where the closed-loop poles are placed are searched so that control performance of the semi-active control system based on the output emulation approach is optimized. © Copyright 2015 John Wiley & Sons, Ltd.


Matsuoka T.,Meiji University | Sugita T.,Meiji University | Sunakoda K.,Sanwa Tekki Co.
American Society of Mechanical Engineers, Pressure Vessels and Piping Division (Publication) PVP | Year: 2014

The authors propose a Magneto-Rheological (MR) fluid damper that utilizes multi pole electromagnets in order to control variable damping effect such as a semiactive damper. The damper consists of a piston, a cylinder, a by-pass pipe, 8 electromagnets, and MR fluid. The electromagnets are installed octagonal around the pipe. When each electromagnet can control both of the magnetic flux density and direction, resisting force can be switched by several types of magnetic field such as artificial orifice. The test damper is manufactured. Resisting force characteristics are measured by using a shaking actuator. Finally, dynamic performance of the damper is confirmed experimentally. Copyright © 2014 by ASME.


Nakamura Y.,Shimizu Corporation | Fukukita A.,Shimizu Corporation | Tamura K.,Chiba Institute of Technology | Yamazaki I.,Sanwa Tekki Corporation | And 3 more authors.
Earthquake Engineering and Structural Dynamics | Year: 2014

This paper presents a new type of electromagnetic damper with rotating inertial mass that has been developed to control the vibrations of structures subjected to earthquakes. The electromagnetic inertial mass damper (EIMD) consists of a ball screw that converts axial oscillation of the rod end into rotational motion of the internal flywheel and an electric generator that is turned by the rotation of the inner rod. The EIMD is able to generate a large inertial force created by the rotating flywheel and a variable damping force developed by the electric generator. Device performance tests of reduced-scale and full-scale EIMDs were undertaken to verify the basic characteristics of the damper and the validity of the derived theoretical formulae. Shaking table tests of a three-story structure with EIMDs and earthquake response analyses of a building with EIMDs were conducted to demonstrate the seismic response control performance of the EIMD. The EIMD is able to reduce story drifts as well as accelerations and surpasses conventional types of dampers in reducing acceleration responses. © 2013 John Wiley & Sons, Ltd.


Hiramoto K.,Niigata University | Matsuoka T.,Meiji University | Sunakoda K.,Sanwa Tekki Corporation
Proceedings of the SICE Annual Conference | Year: 2013

As a method for semi-Active control of structural systems, the active-control-based method that emulates the control force of a targeted active control law by semi-Active control devices has been studied. In the active-control-based method, the semi-Active control devices are not necessarily able to generate the targeted active control force because of the dissipative nature of those devices. In this study, a new semi-Active control strategy that approximates the control output of the targeted active control is proposed. The variable parameter of the semi-Active control device is selected at every time instant so that the predicted control output of the semi-Active control system becomes close to the corresponding predicted control output of the targeted active control as much as possible. Parameters of the targeted active control law are optimized in the premise of the above "output emulation" strategy so that the control performance o f the semi-Active control becomes good and the "error" of the achieved control performance between the targeted active control and the semi-Active control becomes small.


Hiramoto K.,Niigata University | Matsuoka T.,Meiji University | Sunakoda K.,Sanwa Tekki Corporation
Structural Control and Health Monitoring | Year: 2014

SUMMARY Various semi-active control methods have been proposed for vibration control of civil structures. In contrast to active vibration control systems, all semi-active control systems are essentially asymptotically stable because of the stability of general structural systems with structural damping and the energy dissipative nature of the semi-active control itself. In this study, by utilizing the aforementioned property on the stability of semi-active control systems, a structural model for the semi-active control design and a model-based semi-active control law are simultaneously designed so that the control performance of the resulting semi-active control system becomes good. The model for the control system design is assumed to be a linear parameter varying model with adjustable structural design parameters. The semi-active control law is based on the one step ahead prediction of the structural response of the designed model for the control system design. A genetic algorithm is adopted to obtain design parameters in the model for the control system design and the semi-active control law. Those design parameters are optimized so that the closed-loop system with the detailed dynamic model that accurately approximates the dynamic behavior of the real structural system and the semi-active control law obtained with the model for the control system design. The effectiveness of the present approach is shown with a simulation study. Copyright © 2013 John Wiley & Sons, Ltd. Copyright © 2013 John Wiley & Sons, Ltd.


Shibuya Y.,Akita University | Nasuno H.,Shimizu Corporation | Sunakoda K.,Sanwa Tekki Corporation
ASME 2014 Conference on Smart Materials, Adaptive Structures and Intelligent Systems, SMASIS 2014 | Year: 2014

Magneto-rheological composites with magnetic particles are prepared. The magnetic particle is Fe-Si-B-Cr system and the average diameter is 10 m. Matrix of the composite is silicon gel. We characterized dynamic response of the material by shear test in magnetic field where intensities are 0 mT, 105 mT and 211 mT. The stiffness and damping capacity of the composite increase with increasing of the magnetic field. To understand mechanism of behavior of magneto-rheological composites, we make a model of the composite with periodical micro structure. The magneto- rheological composite undergoes magnetically induced internal stress field by applied magnetic field. The analysis model involved effect of the applied magnetic field as initial stress in the material. Particles and the magnetically induced stress make locally large strain field in the gel material. A large deformation analysis with the Ogden model using finite element method is made to demonstrate behavior of magneto-rheological composites. The simulation results are compared with experiment results and verified the effectiveness of the model. Copyright © 2014 by ASME.


Sodeyama H.,Sanwa Tekki Corporation | Mizuma H.,Sanwa Tekki Corporation | Nakatsu M.,Sanwa Tekki Corporation
American Society of Mechanical Engineers, Pressure Vessels and Piping Division (Publication) PVP | Year: 2014

The authors have developed a new pipe support, which is intended for use as an anchor of piping system in power plants. This anchor type support takes a pipe between two-tiered metal blocks and ideally restraints the pipe movement with six degrees of freedom, namely all directions of the piping movement. The four bolts adequately join the two-tiered metal block of the anchor type support with the pipe that is not subjected to unnecessary stress. The internal shape of the two-tiered metal block is designed to stabilize the pipe firmly by increasing area of contact between the pipe and the support. Developing the four-point support design for the internal shape of the blocks has also reduced the stress on the pipe. The restraint forces and restraint moments of the support have been investigated and the verification testing has been conducted for the restraining capability. The relaxation of the bolted joint over time and thermal influence on the relaxation has been also studied experimentally. Since no welding operation on the pipe is required for installation of this anchor support, reduction of time and labor is expected for both a combination of planning and construction of an anchor on piping system. Copyright © 2014 by ASME.


Ito M.,Kobe University | Yoshida S.,Kobe University | Fujitani H.,Kobe University | Sato Y.,Sanwa Tekki Corporation
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2015

The dynamic characteristics of mid-story isolated buildings and seismic response reduction due to a semi-active control system were investigated using a three-lumped-mass model that simplified the sixteen story building with an isolation layer in the sixth story. A semi-active control method using a rotary inertia mass damper filled with magnetorheological fluid (MR fluid) was proposed. The damper shows both mass amplification effect due to rotational inertia and variable damping effect due to the MR fluid. The damping force is controlled by the strength of the magnetic field that is applied to the MR fluid. It is determined by using the electric current, which is calculated by the proposed semi-active control method based on the velocity of the isolation layer relative to the layer just underneath it. Real-time hybrid tests using an actual damper and simulations using a building model were conducted to check the damper model; the test results were in good agreement with the simulation results. The simulation results suggest that the response displacement of the structure above the isolation layer is significantly reduced, without increasing the response acceleration of the entire structure against near-fault pulse and long-period ground motions. The proposed semi-active control using an MR rotary inertia mass damper was confirmed to be effective for mid-story isolated buildings. © 2015 SPIE.


Patent
Kozo Keikaku Eng. Inc. and Sanwa Tekki Corporation | Date: 2013-12-27

A device for damping a transmitted vibration by the moment of inertia of a fly wheel and the adjustable resistance force of a viscous magnetic fluid to allow the viscous magnetic fluid exerts its property even under no external power source. A sleeve with an attached ball nut is disposed in a first cylinder so as to reciprocate. The reciprocating motion of the sleeve is converted into a rotational motion by a ball screw to rotate a fly wheel in a second cylinder and a generator rotating shaft. Between the fly wheel and the inner surface of the second cylinder, a sealed space is formed in which a viscous magnetic fluid is sealed. A magnetic field generating unit which generates a magnetic field running across the sealed space with the fly wheel serving as a part of a magnetic circuit is disposed on the inner circumference of the second cylinder.


Trademark
Sanwa Tekki Corporation | Date: 2011-07-26

metal pipe and instrument supports, namely, pipe hangers, hydraulic snubbers and mechanical snubbers.

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