scholarly journals EQUIVALENT LINEARIZATION OF PASSIVE CONTROL SYSTEM WITH OIL DAMPER BILINEARLY DEPENDENT ON VELOCITY

Author(s):  
Kazuhiko KASAI ◽  
Tadamune NISHIMURA
2018 ◽  
Vol 148 ◽  
pp. 416-423 ◽  
Author(s):  
T. Capurso ◽  
G. Menchise ◽  
G. Caramia ◽  
S.M. Camporeale ◽  
B. Fortunato ◽  
...  

Author(s):  
BG Kavyashree ◽  
Shantharam Patil ◽  
Vidya S. Rao

AbstractPermanent construction has evolved from the Palaeolithic age to today’s skyscrapers. Constructing the structure, which promises occupants safety, has become a concern because of the uncertainties in nature. Therefore in recent years, attention has been given to the development of structural protective devices that could take care of the external loads. Structural control against the wind and earthquake load has been seriously studied where the structure behaves differently for wind and earthquake load has been briefly discussed in this paper. Initially, paper discusses the history of the construction and the passive control system, which was used in structural control, is briefly discussed in this paper. Also, the implementation of active control has been discussed which was introduced later in the structural control for more effective control. But the limitations of the passive and active control system have introduced semi-active control and also the hybrid control strategy. The two mechanisms are put together in the semi-active and hybrid system to obtain all advantages of the algorithm along with overcoming their limitations. The review also briefs about stochastic vibrational control of the structure where randomness is considered in external loads, parameter of the system and also in the external devices which are implemented in the structural control. As construction sector is a complex system, big data analysis, a new field in structural control system is discussed and future scope is also mentioned.


2019 ◽  
Vol 9 (4) ◽  
pp. 688 ◽  
Author(s):  
Luyu Li ◽  
Qigang Liang ◽  
Han Qin

Inerter-based dampers have gained great popularity in structural vibration control. In this paper, equivalent linearization methods (ELMs) for a single-degree-of-freedom (SDOF) system with a clutching inerter damper (CID) are studied. The comparison of a SDOF system with a CID and an inertial mass damper (IMD) shows the advantage of the CID. Considering that the system with the CID is nonlinear, which is problematic for its performance evaluation and the integrated design of the structure and control system, three equivalent linearization methods based on different principles are proposed and discussed in this paper. The CID is considered to be equal to a combination of an IMD and a viscous damper. The equivalent inertance and damping can be calculated using the obtained formulas for all methods. In addition, all methods are compared in a numerical study. Results show that the ELM based on period and energy is recommended for small inertance-mass ratios.


Author(s):  
Liang Liu ◽  
Tao Zhou ◽  
Jie Chen ◽  
Ali Shahzad Muhammad ◽  
Juan Chen ◽  
...  

In this paper, operating characteristics of the safety system of Chinese Supercritical Water-cooled Reactor (CSR1000) is described. Selecting CSR1000 as the focus of research, and it’s active and passive safety systems are analyzed in turn. A comparison is given between these two types of safety systems. Henceforth, the features of the safety control systems of CSR1000 are obtained. The results show that for the active systems, the control speed of the pressure control system is the fastest and that of the power control system is the slowest. It is observed that the active control system exhibits simple harmonic oscillation. On the other hand, the control feature of passive control system is stable. In addition, coupling the safety systems can ensure the safety of CSR1000 in the event of a loss of flow accident (LOFA).


2015 ◽  
Vol 2015 ◽  
pp. 1-6
Author(s):  
Jesús U. Liceaga-Castro ◽  
Irma I. Siller-Alcalá ◽  
Eduardo Liceaga-Castro ◽  
Luis A. Amézquita-Brooks

Via several cases of study it is shown that a passive multivariable linear control system, contrary to its single input single output counterpart, may not be robust. Moreover, it is shown that lack of robustness can be exposed via the multivariable structure function.


1999 ◽  
Vol 15 (2) ◽  
pp. 317-330 ◽  
Author(s):  
Yuri Ribakov ◽  
Jacob Gluck

Incorporated at various levels of a structural frame, ADAS devices may be used to improve the response of the structure during earthquakes. A design method of a passive control system for multistory structures using optimal Adding Damping And Stiffness (ADAS) dampers is presented. Optimal Control Theory (OCT) is commonly used to obtain the levels of viscous damping at each story. The optimization leads to different levels of damping at each story. Therefore, a solution with viscous dampers is inconvenient and can be expensive. The proposed method enables the use of relatively less expensive optimal ADAS devices dissipating energy which is equivalent to that of viscous dampers. The method is examined in a numerical analysis of a seven-story shear framed structure. Significant improvement was obtained in the behavior of the ADAS damped structure compared to the uncontrolled one.


2005 ◽  
Vol 128 (3) ◽  
pp. 364-369 ◽  
Author(s):  
Y. M. Parulekar ◽  
G. R. Reddy ◽  
K. K. Vaze ◽  
K. Muthumani

Passive energy dissipating devices, such as elastoplastic dampers (EPDs) can be used for eliminating snubbers and reducing the response of piping systems subjected to seismic loads. Cantilever and three-dimensional piping systems were tested with and without EPD on shaker table. Using a finite element model of the piping systems, linear and nonlinear time-history analysis is carried out using Newmark’s time integration technique. Equivalent linearization technique, such as Caughey method, is used to evaluate the equivalent damping of the piping systems supported on elastoplastic damper. An iterative response spectrum method is used for evaluating response of the piping system using this equivalent damping. The analytical maximum response displacement obtained at the elastoplastic damper support for the two piping systems is compared with experimental values and time history analysis values. It has been concluded that the iterative response spectrum technique using Caughey equivalent damping is simple and results in reasonably acceptable response of the piping systems supported on EPD.


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