The characterization of damping is important in making accurate predictions of both the true response and the frequency response of any device or structure dominated by energy dissipation. The process of modeling damping matrices and experimental verification of those is challenging because damping can not be determined via static tests as can mass and stiffness. Furthermore, damping is more di...

The well-known electro-mechanical analogy that equates current, voltage, resistance, inductance and capacitance to force, velocity, damping, spring constant and mass has a shortcoming in that mass can only be used to simulate a capacitor which has one terminal connected to ground. A new model that was previously proposed by the authors that combines a mass with a pulley (MP) is shown to simulat...

It is very well known that tuned mass dampers are engineered to minimise the vibrations in buildings in earthquake prone areas and in some cases machinery [1]. This paper evaluates the utility of Tuned Mass Dampers in passenger cars. For the same suspension system, addition of a tuned mass was found to reduce the transmissibility by a considerable amount. Addition of a tuned mass also helps in ...

The contribution of foundation damping to offshore wind turbines (OWTs) is not well known, though researchers have back-calculated foundation damping from “rotor-stop” tests after estimating aerodynamic, hydrodynamic, and structural damping with numerical models. Because design guidelines do not currently recommend methods for determining foundation damping, it is typically neglected. This pape...

The contribution of foundation damping to offshore wind turbines (OWTs) is not well known, though researchers have back-calculated foundation damping from “rotor-stop” tests after estimating aerodynamic, hydrodynamic, and structural damping with numerical models. Because design guidelines do not currently recommend methods for determining foundation damping, it is typically neglected. This pape...

The present study reports the influence of fiber orientation, laminate sequence and fabric type on the inherent nonlinearity of intact carbon fiber/epoxy composites using nonlinear resonant ultrasonic spectroscopy (NRUS) [1-2]. Fiber orientation of the CFRP samples were changed relative to the length of the sample. Since the fundamental flexural mode is excited, the properties of the composite ...

Optimization is important in physical and engineering sciences for the problems such as Lagrangian formalism in mechanics, finding the optimal electron density in quantum chemistry, designing minimum-cost networks in computer science. Searching for global minima by overcoming local minima is a fundamental issue in optimization. This dissertation develops adaptive annealing methods which are phy...

A new method of parameter identification based on linear time-frequency representation and Hilbert transform is proposed in this paper to identify modal parameters of linear time-varying systems from measured vibration responses. With Gabor expansion and synthesis theory, measured responses are represented in time-frequency domain and modal components are reconstructed by time-frequency filteri...

We consider the dynamical evolution of two planets with nearly circular and nearly coplanar orbits undergoing eccentricity damping and convergent migration in the vicinity of a first order mean motion resonance. Following Goldreich & Schlichting, we include a coupling between the dissipative semimajor axis evolution and the damping of the eccentricities. In agreement with past studies, we find ...