Thesis (M.S.)--Ohio University, August, 1997. / Title from PDF t.p.

Dissertation (Ph.D.)--Worcester Polytechnic Institute. / Keywords: hybrid system, PZT actuators, performance enchancement, actuator placement, actuator switching. Includes bibliographical references (leaves 102-108).

Large, ``rigid'' structures made of interconnecting beams and tendons represent a type of construction that has many engineering benefits. Lightweight, strong, and generally constructed of standard-shaped metal framework, they also incur significant challenges to control vibration. The construction that makes them strong, light, and ``rigid'' also makes them have very small inherent structural damping, and highly-complex modal structure. A myriad of control techniques have been developed to work on this problem with success usually in very small bandwidths related to a specific frequency ``hot-spot'' around a few specific modes. This work describes the design, analysis, and implementation of a novel controller configuration applicable to broadband vibration suppression on a large, uncertain resonant structure. The measurement, identification, characterization, and modeling of a large, flexible, lightly-damped test structure with in excess of 1000 modes in 50-5000Hz range was used as the basis for choosing a control configuration. This choice leverages the relative benefits of different control types to obtain one with a combination of the best features of all of them. High-order and low-order feedback, and feed-forward controller configurations were all used in different frequency ranges. Real design tradeoffs such as computation complexity, model accuracy, and available actuator technologies were fundamental to the design choices. Measured individual modal reduction was as much as 15dB for feedback control, 20dB for feed-forward control, and 4dB broadband over the range of 50-5000Hz. / Ph. D.

Thesis (M.S.)--Ohio University, March, 2000. / Title from PDF t.p.

Thesis (Ph. D.)--Marquette University, 2009. / Access available to Marquette University only. Available for download on June 17, 2010. Robert J. Stango, Nicholas J. Nigro, Stephen Heinrich, Vikram Cariapa, Shuguang Huang, Advisors.

Thesis (M. Arch.)--University of Hong Kong, 2004. / Includes special report study entitled: On mobile architecture, towards mobile urbanism. Also available in print.

Thesis (M. Arch.)--University of Hong Kong, 2004. / Includes special report study entitled: Movable architecture: a study of movable environment in the past, present and future. Also available in print.

No description available.

Structural vibration control (SVC) of large scale structures using the magnetorheological (MR) dampers are studied. Some key issues, i.e. model reduction, suppression of spillover instability, optimal placement of actuators and sensors, modeling of the MR dampers and their applications in SVC system for large scale structures, are addressed in this work. A new model reduction method minimizing the error of a modal-truncation based reduced order model (ROM) is developed. The proposed method is implemented by using a Genetic Algorithm (GA), and can be efficiently used to find a ROM for a large scale structure. The obtained ROM has a finite H2 norm and therefore can be used for H2 controller design. The mechanism of the spillover instability is studied, and a methodology to suppress the spillover instability in a SVC system is proposed. The suggested method uses pointwise actuators and sensors to construct a controller lying in an orthogonal space spanned by the several selected residual modes, such that the spillover instability caused by these residual modes can be successfully suppressed. A GA based numerical scheme used to find the optimal locations for the sensors and actuators of a SVC system is developed. The spatial H2 norm is used as the optimization index. Because the spatial H2 norm is a comprehensive index in evaluating the dynamics of a distributed system, a SVC system using the sensors and actuators located on the obtained optimal locations is able to achieve a better performance defined on a distributed domain. An improved model of MR dampers is suggested such that the model can maintain the desired hysteresis behavior when noisy data are used. For the simulation purpose, a numerical iteration technique is developed to solve the nonlinear differential equations aroused from a passive control of a structure using the MR dampers. The proposed method can be used to simulate the response of a large scale structural system with the MR dampers. The methods developed in this work are finally verified using an industrial roof structure. A passive and semi-active SVC systems are designed to attenuate the wind-induced structural vibration inside a critical area on the roof. The performances of the both SVC systems are analyzed and compared. Simulation results show that the SVC systems using the MR dampers have great potentials in reducing the structural vibration of the roof structure.

This paper considers the control of externally symmetric vector second order systems using an analytical upper bound method. The structural model is a cantilevered aluminum beam with a collocated pair of piezoceramic patches to serve as actuators and sensors. A computationally efficient method for approximating the H-infinity norm for externally symmetric systems is presented. The approximation method is then used to calculate a scalar output feedback controller to guarantee a closed-loop norm less than any user defined value. This method is tested with a finite-element representation of the beam, and then verified experimentally.