This paper analyses the damping in pressure compensated closed centre mobile working hydraulic systems. Both rotational and linear loads are covered and the analysis applies to any type of pump controller. Only the outlet orifice in the directional valve will provide damping to a pressure compensated system. Design rules are proposed for how the system should be dimensioned in order to obtain a...

The paper describes an investigation of the effect of structural damping in the torsion mode on wing flutter with the object of finding circumstances in which damping reduces the flutter speed. The drop in flutter speed can be considerable (25 per cent) and extend to very large values of structural damping. The effect is most apparent when the relative density (wing to air) is high, and when th...

biological control of sugar beet damping-off of rhizoctonia solani ag-4 by two native streptomyces isolates (s2 and c) was evaluated in green house and field conditions. in dual culture, two streptomyces isolates inhibited mycelial growth of r. solani ag-4. besides, volatile components of s2 and c inhibited r. solani mycelial growth for 72 and 74 percentages, respectively. soil treatment either...

shear modulus and damping ratio are important input parameters in dynamic analysis. a series of resonant column tests was carried out on pure clays and sand-clay mixtures prepared at different densities to investigate the effects of aggregate content, confining stress, void ratio and clay plasticity on the maximum shear modulus and minimum damping ratio. test results revealed an increase in the...

The speed of the Levenberg–Marquardt ~LM! nonlinear iterative least-squares method depends upon the choice of damping strategy when the fitted parameters are highly correlated. Additive damping with small damping increments and large damping decrements permits LM to efficiently solve difficult problems, including those that otherwise cause stagnation. © 1997 American Institute of Physics. @S089...

Film damping caused by microfluids has important effects on the dynamic characteristics of moving elements of microelectromechanical system devices. There are two kinds of film damping existing in microelectromechanical system devices, for instance, slide film damping and squeeze film damping. This article presents an overview on the recent research progress on the slide film damping in microel...

Thermo-elastic damping is a significant dissipation mechanism in high quality factor microstructures. In this paper, thermo-elastic damping of the in-plane vibration of fully clamped rectangular micro-plates has been studied. The governing equation of the micro-plate motion and heat conduction equation were derived. Then, The Galerkin method has been used to solve the coupled heat-displacement ...

In this paper, we present a novel parametric model based on an important evolution of McAulay & Quatieri sinusoidal models [5]. This model takes into account a damping factor as well as a delay parameter which makes it more efficient for modeling strong audio transients such as castanets onsets without pre-echo effects. We also develop an original algorithm to estimate the model parameters by m...

In this paper we consider a multi-dimensional wave equation with dynamic boundary conditions related to the Kelvin-Voigt damping and a delay term acting on the boundary. If the weight of the delay term in the feedback is less than the weight of the term without delay or if it is greater under an assumption between the damping factor, and the difference of the two weights, we prove the global ex...

Abstract The identification of the modal parameters from frequency response functions is a subject that is not new. However, the starting point often comes from the equations that govern the dynamic motion. In this paper, a novel approach is shown, resulting from an analysis that starts on the dissipated energy per cycle of vibration. Numerical and experimental examples were used in order to as...