Vibration Control Of Structural Systems Research Articles

Active-Control and Forced-Vibration Studies on Highway Bridge

A full-scale, active, structural vibration-control system was successfully implemented and tested on an 80-m (250 ft) span, steel-truss highway bridge. More than 90% reduction in global mode response was achieved during testing using random, sinusoidal, and step-release disturbance excitations. Control performance was maintained in the presence of large changes in the dynamic characteristics of the structure due to environmental effects. This study demonstrated the feasibility and reliability of a new approach to active structural vibration-control–adaptive modal filter (AMF) based independent modal space control (IMSC). This work identified and explored many of the practical problems that must be addressed for commercial control installations on civil facilities to be viable.

A Note on Local Behavior of Multiple Eigenvalues

This note is a continuation of the work in [J. Comput. Math., 6 (1988), pp. 28–38]. The directional derivatives of multiple eigenvalues of a symmetric eigenproblem analytically dependent on several parameters are given. The result can be used to define the sensitivity of multiple eigenvalues, and it is useful for investigating structural vibration design and control system design.

Modified Independent Modal Space Control Method for Active Control of Flexible Systems

A modified independent modal space control (MIMSC) method is developed for designing active vibration control systems for large flexible structures. The method accounts for the interaction between the controlled and residual modes. It also incorporates optimal placement procedures for selecting the optimal locations of the actuators in the structure in order to minimize the structural vibrations as well as the actuation effort. The MIMSC method relies on an important feature which is based on ‘time sharing’ of a small number of actuators, in the modal space, to control effectively a large number of modes. Numerical examples are presented to illustrate the application of the method to generic flexible systems. The obtained results suggest the potential of the devised method in designing efficient active control systems for large flexible structures.