This paper presents numerical studies of friction-induced instabilities of brake systems using complex mode analysis. The complex eigenvalue extraction is performed at a deformed configuration; thus, nonlinear effects are taken into account in the modal analysis. An example case is used to illustrate the importance of friction-induced damping and nonlinear effects in brake squeal analysis. It i...

This paper concerns the optimization and coordination of the conventional FACTS (Flexible AC Transmission Systems) damping controllers in multimachine power system. Firstly, the parameters of FACTS controller are optimized. Then, a hybrid fuzzy logic controller for the coordination of FACTS controllers is presented. This coordination method is well suitable to series connected FACTS devices lik...

In this paper we develop an efficient numerical method for the finite-element model updating of damped gyroscopic systems based on incomplete complex modal measured data. It is assumed that the analytical mass and stiffness matrices are correct and only the damping and gyroscopic matrices need to be updated. By solving a constrained optimization problem, the optimal corrected symmetric damping ...

A modal decomposition is used to study the coupled longitudinal motion of electron bunches in a storage ring. The decomposition allows the simultaneous measurement of growth rates and (feedback induced) damping rates of all unstable beam modes via a time-domain transient technique. The damping rates of naturally stable modes are measured via a related external transient technique. The measured ...

A number of compressor design modifications to reduce the noise which are based on the modal characteristics of the compressor shell are discussed and special problems are pointed out. Most design changes exhibit effects across broad frequency regions and while reducing the noise in some frequency bands can cause noise increases in other bands. Shell damping was found to be a generally consiste...

Expressions for piezoelectric inductive-resistive shunt tuning to a targeted structure mode are obtained by explicit frequency response functions, derived from combined short- and open-circuit modal representation that accounts inherent structural damping. The influence of external loading is further included accounting the short-circuit dynamic quasi-static contributions modes below above targ...

This paper proposes a novel ungrounded TMDI to improve the vibration suppression performance of transmission line under harmonic excitation. type inerter-based damper may transform translational motion into rotational motion, greatly increasing efficiency suppression. In present study, differential equations are first derived based on with an structure. Then closed-form solution displacement re...