排序方式： 共有39条查询结果，搜索用时 15 毫秒
31.
Michele Palermo Stefano Silvestri Tomaso Trombetti Luca Landi 《Bulletin of Earthquake Engineering》2013,11(5):1661-1681
This research work focuses on the analysis of the hysteretic seismic behaviour of inelastic SDOF systems equipped with viscous dampers. In detail, it is aimed at obtaining a practical tool useful for the seismic design of building structures with added dampers, within the framework of the traditional seismic design based on ductility. The objective is to evaluate the appropriate force reduction factor for highly damped (i.e. damping ratio greater than 5 %) SDOF systems able to guarantee a prescribed level of structural safety. 相似文献
32.
On the dimensioning of viscous dampers for the mitigation of the earthquake-induced effects in moment-resisting frame structures 总被引：1，自引：1，他引：0
Michele Palermo Saverio Muscio Stefano Silvestri Luca Landi Tomaso Trombetti 《Bulletin of Earthquake Engineering》2013,11(6):2429-2446
The effectiveness of viscous dampers in mitigating the seismic excitation impacts upon building structures has been widely proved. Recently, with reference to the specific case of equal mass, equal stiffness, shear-type structures, the authors developed a direct practical procedure which gives the mechanical characteristics of the manufactured viscous dampers capable of providing the frame structure with a prescribed value of the first damping ratio. In this paper, a comprehensive rational framework is presented, which allows to formally extend the validity of the proposed procedure to the more realistic case of a generic moment-resisting frame structure. Also the influence of various lateral stiffness distributions is investigated. 相似文献
33.
Jeroen Homan Rudy Wijnands Albert Kong Jon M. Miller Sabrina Rossi Tomaso Belloni Walter H. G. Lewin 《Monthly notices of the Royal Astronomical Society》2006,366(1):235-237
We report the result of an XMM–Newton observation of the black hole X-ray transient XTE J1650–500 in quiescence. The source was not detected, and we set upper limits on the 0.5–10 keV luminosity of 0.9–1.0 × 1031 erg s−1 (for a newly derived distance of 2.6 kpc). These limits are in line with the quiescent luminosities of black hole X-ray binaries with similar orbital periods (∼7–8 h). 相似文献
34.
35.
36.
This paper focuses on the development of a linear analytical model (even though servo‐hydraulic actuation systems are inherently non‐linear, especially for large amplitude simulations — near the performance capacity of the system — linearized models proved experimentally to be quite effective overall in capturing the salient features of shaking table dynamics) of a uni‐axial, servo‐hydraulic, stroke controlled shaking table system by using jointly structural dynamics and linear control theory. This model incorporates the proportional, integral, derivative, feed‐forward, and differential pressure gains of the control system. Furthermore, it accounts for the following physical characteristics of the system: time delay in the servovalve response, compressibility of the actuator fluid, oil leakage through the actuator seals and the dynamic properties of both the actuator reaction mass and test structure or payload. The proposed model, in the form of the total shaking table transfer function (i.e. between commanded and actual table motions), is developed to account for the specific characteristics of the Rice University shaking table. An in‐depth sensitivity study is then performed to determine the effects of the table control parameters, payload characteristics, and servovalve time delay upon the total shaking table transfer function. The sensitivity results reveal: (a) a potential strong dynamic interaction between the oil column in the actuator and the payload, and (b) the very important effect of the servovalve time delay upon the total shaking table transfer function. Copyright © 2000 John Wiley & Sons, Ltd. 相似文献
37.
A procedure is described for analysing the transport equations for Reynolds stresses written in a streamline coordinate system, starting from the fields of first- and second-order moments of wind velocity measured in a terrain-following system over topography. In the analysis, the equations are split into two parts: the first contains the terms that can be calculated directly from measurements; the second contains third-order moments that are parameterized using suitable models. To evaluate the error associated with both parts, a Monte-Carlo technique that takes into account the experimental errors is proposed. An example of the application of this method for the Reynolds shear stress equation, using wind-tunnel data for non-separating flow over a two-dimensional valley, is reported. The comparison between the measured and modelled parts is fair near the surface, while at higher levels, the modelled part can be shown to miss a correct treatment of the third-order moments. In the frame of this analysis, the use of the correct derivative transformation has been found to be significant even for moderately sloping topography. 相似文献
38.
Seismic Modal Contribution Factors 总被引：1，自引：0，他引：1
Michele Palermo Stefano Silvestri Giada Gasparini Tomaso Trombetti 《Bulletin of Earthquake Engineering》2015,13(10):2867-2891
39.