—Converter-interfaced power sources (CIPSs), like wind turbine and energy storage, can be switched to the inertia emulation mode when the detected frequency deviation exceeds a pre-designed threshold, i.e. dead band, to support the frequency response of a power grid. This letter proposes an approach to derive the emulated inertia and damping from a CIPS based on the linearized model of the CIPS...

The least squares adjustment (LSA) method is studied as an optimisation problem and shown to be equivalent to the undamped Gauss-Newton (GN) optimisation method. Three problem-independent damping modifications of the GN method are presented: the line-search method of Armijo (GNA); the LevenbergMarquardt algorithm (LM); and Levenberg-Marquardt with Powell dogleg (LMP). Furthermore, an additional...

The article presents an axi-symmetrical model for determining the total damping coefficient of a periodic perforated microelectromechanical systems (MEMS) microstructure for cases where the lubrication approximation yielding the Reynolds’ equation is no longer appropriate. Damping is modeled by solving for the viscous flow in an approximation of the periodic cell geometry using an equivalent ax...

The dynamic response of a series of base-isolated systems subjected to ground motions that were recorded in firm soils located inshore of the Mexican Pacific was estimated in order to evaluate the influence of the structural properties of these systems in their floor acceleration demands. While the super-structures were assumed to remain elastic, the energy dissipation capacity of the base-isol...

We consider a mathematical model of a linear vibrational system described by the second-order system of differential equations Mẍ +Dẋ+Kx = 0, where M, K and D are positive definite matrices, called mass, stiffness and damping, respectively. We are interested in finding an optimal damping matrix which will damp a certain part of the undamped eigenfrequencies. For this we use a minimization crite...

A multi-panel PMC infilled system, using polymer matrix composite (PMC) material, was introduced as new conceptual design for seismic retrofitting. A proposed multi panel PMC infilled system was composed of two basic structural components: inner PMC sandwich infills and outer FRP damping panels. The PMC material had high stiffness-to-weight and strength-to-weight ratios. Therefore, the addition...

It is desirable to obtain materials that have high vibration damping while maintaining other structural properties. Aerospace quality composite materials typically have greater strength and stiffness to weight ratios than most metals, while providing increased damping. However, their passive damping capacities are not enough for some applications. Fiber reinforced elastomers (FRE) or elastomer ...

1. Abstract An efficient damping layout optimization method of structural-acoustic systems is proposed to minimize acoustic responses using a gradient-based optimization algorithm. To analyze vibro-acoustic systems, a hybrid model that uses finite elements for the structures and boundary element for the cavity is developed. The four-parameter fractional derivative model is used to represent the...

The maximum a posteriori (MAP) configuration of binary variable models with submodular graph-structured energy functions can be found efficiently and exactly by graph cuts. Max-product belief propagation (MP) has been shown to be suboptimal on this class of energy functions by a canonical counterexample where MP converges to a suboptimal fixed point (Kulesza & Pereira, 2008). In this work, we s...

This paper presents investigations of two special cases of dynamic valve analysis. These special cases arose in the development of a new type of gas field reciprocating compressor. These special cases were for a moving frame of reference (since the discharge valves were integral with the piston) , and for independent mass damping {sealing/damping elements are modelled separately instead of as "...