Abstract: Wind turbine blades have to withstand the rigorous test of 20–25 years of service. Fatigue testing is an accurate method used to verify blade reliability. Multi-point excitation could better fit the fatigue damage distribution, which reduces the power output of a single exciter and saves testing energy consumption. The amplitude, phase, and frequency characteristics of the fatigue tes...

The online parametric identification of deteriorating and non-deteriorating distributed element models (DEMs) with viscous damping is studied using a generalization of Masing model to provide the proper framework for identification. The approach renders the hysteretic response of the DEM into a time-independent single-valued mapping from equivalent displacement values into equivalent force valu...

We study the relation between PageRank and other parameters of information networks such as in-degree, out-degree, and the fraction of dangling nodes. We model this relation through a stochastic equation inspired by the original definition of PageRank. Further, we use the theory of regular variation to prove that PageRank and in-degree follow power laws with the same exponent. The difference be...

We present a four-body semileptonic charm decay D → Kπμν analysis in the range of 0.65 GeV/c < mKπ < 1.5 GeV/c . We observe a low mass scalar contribution of 5.30 ± 0.74 0.99 − 0.96% with respect to the total D →Kπμν decay, compatible with the phase shift found by the LASS elastic scattering experiment. For the K(892) resonance, we obtain a mass of 895.41 ± 0.32 − 0.43 MeV/c , a width of 47.79 ...

in this paper, the unified power flow controller (upfc) is enhanced with a chaotic particle swarm optimization (cpso) damping controller in order to mitigate the low frequency oscillations (lfo) in a single machine infinite bus (smib) power system. the designed damping controller is an optimized lead-lag controller, which extracts the speed deviation of the generator rotor and generates the out...

The damping ratio of chassis suspension is a key parameter for damping matching of in-wheel motor vehicles (IWMVs). Because the motor is attached to the driving wheel, the initial design method of the damping ratio for traditional cars is not entirely suitable for IWMVs. This paper proposes an innovative initial design method of the damping ratio for IWMVs. Firstly, a traveling vibration model ...

It is shown that among the various damping mechanisms that are generally encountered in a mechanical structure, only the “viscous component” actually accounts for energy loss. The remaining portion of the damping force is due to non-linearities, which do not dissipate energy. Consequently, a linear model of a vibratory mechanical system involves only viscous damping, although the damping factor...

This study proposes a capacity spectrum Method (CSM)-based procedure to estimate the maximum seismic performance of steel buildings passively controlled with bilinear oil dampers. In proposed CSM, response building was estimated, in acceleration-displacement spectrum, as intersection between curve and damping-adjusted demand curves, using equivalent linearization method. The damping ratio deter...

The dynamic characteristics of joint interfaces have significant effect on both static and dynamic behaviors of the whole machine tool structures. Its dynamic model can be simplified as a group of equivalent spring-damping elements, that is, an ‘elastic interlayer’ without mass. The unit area dynamic characteristic parameters are the key to analyze the dynamic properties of joint interfaces. Ho...