Dynamic force control with hydraulic actuators using added compliance and displacement compensation |
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| Authors: | Mettupalayam V Sivaselvan Andrei M Reinhorn Xiaoyun Shao Scot Weinreber |
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| Institution: | 1. Department of Civil, Environmental and Architectural Engineering, University of Colorado at Boulder, 428 UCB, Boulder, CO 80309, U.S.A.;2. Department of Civil, Structural and Environmental Engineering, University at Buffalo, Buffalo, NY 14260, U.S.A.;3. Department of Civil, Architectural, Agricultural and Environmental Engineering, North Carolina Agricultural and Technical State University, Greensboro, NC 27411, U.S.A.;4. Formerly Post‐doctoral Research Associate, University at Buffalo. |
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| Abstract: | A new approach to dynamic force control of mechanical systems, applicable in particular to frame structures, over frequency ranges spanning their resonant frequencies is presented. This approach is implemented using added compliance and displacement compensation. Hydraulic actuators are inherently velocity sources, that is, an electrical signal regulates their velocity response. Such systems are therefore by nature high‐impedance (mechanically stiff) systems. In contrast, for force control, a force source is required. Such a system logically would have to be a low‐impedance (mechanically compliant) system. This is achieved by intentionally introducing a flexible mechanism between the actuator and the structure to be excited. In addition, in order to obtain force control over frequencies spanning the structure's resonant frequency, a displacement compensation feedback loop is needed. The actuator itself operates in closed‐loop displacement control. The theoretical motivation, as well as the laboratory implementation of the above approach is discussed along with experimental results. Having achieved a means of dynamic force control, it can be applied to various experimental seismic simulation techniques such as the effective force method and the real‐time dynamic hybrid testing method. Copyright © 2008 John Wiley & Sons, Ltd. |
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| Keywords: | dynamic force control hydraulic actuators natural velocity feedback Smith Predictor advanced seismic testing |
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