A methodology is developed for the design of optimum viscous fluid passive energy dissipation systems using poleassignment active control algorithm. In this method, the procedure to assign the new structural poles is...
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A methodology is developed for the design of optimum viscous fluid passive energy dissipation systems using poleassignment active control algorithm. In this method, the procedure to assign the new structural poles is slightly modified such that the resulting structural properties (i.e., the optimum locations of system poles) can be achieved merely by modification of structural stiffness and addition of a passive control system. A combination of stiffness reduction and increase of damping is utilized to reduce both acceleration and displacement response. It is shown that the control systems designed using this method provide structural performances slightly better than or close to those of ordinarily designed optimum passive systems. Furthermore, by an educated selection of the locations of the structural poles, the proposed method provides more versatility in the design of passive control systems. Copyright (c) 2013 John Wiley & Sons, Ltd.
ABSTARCT A practical procedure is developed for the design of passive control systems using viscous fluid dampers for nonlinear structures. The design methodology takes advantage of the modification of the damping, st...
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ABSTARCT A practical procedure is developed for the design of passive control systems using viscous fluid dampers for nonlinear structures. The design methodology takes advantage of the modification of the damping, strength, and stiffness properties of the structure to achieve the desired relative displacement and absolute acceleration response. For this purpose, a study of poles in the complex plane is used to determine the required changes in the dynamic properties of nonlinear structures. Furthermore, a relatively simple relation between the ductility demands of highly damped single- and multiple-degree-of-freedom (SDF and MDF respectively) systems is established to reduce the computational burden of the proposed design method.
Skewed bridges due to the specific dynamic characteristics have shown vulnerability in recent strong earthquakes. In this study, an active control strategy is employed to optimize the seismic performance of a typical ...
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Skewed bridges due to the specific dynamic characteristics have shown vulnerability in recent strong earthquakes. In this study, an active control strategy is employed to optimize the seismic performance of a typical model of such structures. As the control algorithm, the pole placement method has been used, of which the key factor is selection of desired poles to achieve desired dynamic responses. A performance index (PI) was defined as a function of displacement and rotation of a bridge deck. The desired poles for the algorithm were extracted by optimizing this index. A previously presented and approved simplified model of a skewed bridge with the three degrees of freedom was selected as a typical model, and the methodology was applied on this model. The optimization of PI was carried out by a series of time-history analysis. Ten far-field ground-motion records presented in FEMA-P695 were used for this purpose. The PI was calculated for a range of damping ratio and frequency of the system, and the desired poles were selected for the optimum values of PI. The results show that the control of the model using the selected pole by this method could effectively reduce the displacement and rotation of the bridge model.
This study is concerned with the safe implementation of delayed output feedback (DOF) for linear systems with multiple input delays. It is observed that the numerical implementation of the distributed delay terms invo...
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This study is concerned with the safe implementation of delayed output feedback (DOF) for linear systems with multiple input delays. It is observed that the numerical implementation of the distributed delay terms involved in the DOF controller may lead to instability of the closed-loop system. To solve this problem, a generalised low-pass filter (LPF) is introduced into the control loop. It is shown that the stability of the closed-loop system can be maintained if the numerical integration is sufficiently precise. An augmented system is then constructed to design the LPF by applying the traditional pole assignment algorithm for linear systems without delay. Two illustrative examples are worked out to show the effectiveness of the proposed approach.
In this paper a new proof of the poleassignment theorem is given. This proof is a very straightforward one. It is not based on canonical forms and also the reduction to the single input case (Heymann's lemma) is ...
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In this paper a new proof of the poleassignment theorem is given. This proof is a very straightforward one. It is not based on canonical forms and also the reduction to the single input case (Heymann's lemma) is not used. Furthermore, an algorithm is given which allows to take into account numerical aspects with respect to the feedback construction for the multi-input case. Furthermore the non-uniqueness of the feedback matrix in the multi-input case may be exploited in order to reduce the gains.
A very simple proof of the poleassignment theorem for systems over a principal ideal domain (and other rings) is given. Furthermore, an algorithm is presented. Extensions are also indicated.
A very simple proof of the poleassignment theorem for systems over a principal ideal domain (and other rings) is given. Furthermore, an algorithm is presented. Extensions are also indicated.
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