An analytical and experimental investigation of active vibration control techniques on coupled plate structures

This PhD thesis presents a theoretical and experimental investigation using active control to attenuate the vibration responses associated with coupled plate structures. Three plate structures were examined, which corresponded to an L, T and X shaped plate. The plate theory used to determine the dynamic and controlled responses of the coupled plate structures is presented for a generic structure consisting of four finite plates joined together at right angles in a X-shape. The theory for active vibration control of the coupled plate using single and multiple control actuators and error sensors is also presented for both dependent and independent control. The use of multiple actuators and error sensors in various arrangements to attenuate the response of various coupled plate structures is demonstrated. The number and location of the control forces and error sensors are varied, and their effects on the control performance are compared. In addition, the effect of the control forces driven dependently and independently was investigated. For active control at discrete resonance frequencies, the global response of the structure was observed. Experiments were conducted in order to validate theoretical results on the active control of the global response at a low resonance frequency. The results showed excellent correlation, validating the effectiveness of the active control application. An energy method to predict the vibrational response and its transmission between coupled structures in the medium to high frequency ranges is Statistical Energy Analysis (SEA). In this thesis, SEA is used to model several built-up structures and estimate their vibrational response using energy flow relationships. Energy levels of the L, T, X-shaped plates, and a 7-plate structure, predicted from the exact analytical waveguide model are compared with those of conventional SEA models. A hybrid approach between the two techniques is also presented. The hybrid method uses the analytical waveguide method to estimate the input power and coupling loss factors used in the conventional SEA equations. The energy levels in individual plate subsystems using the exact analytical method, SEA, and the hybrid technique are compared.

Name dc:type.qualificationname

phd

Level dc:type.qualificationlevel

doctoral

Grantor dc:publisher.institution

James Cook University

Year dc:date.issued

2004

Author dc:creator

• Keir, John

Language dc:language

en