Results 261 to 270 of about 47,269 (302)

Modal damping ratio analysis of dynamical system with non-stationary responses

Applied Ocean Research, 2016
Abstract During the long term monitoring of the structure, the damping ratio reflects the characteristics of the structure from perspective of energy loss, and its changes can reflect the structural damages to some extent. But in the structural modal analysis based on the prototype measurement, the damping ratio identification results are difficult ...
Da Tang, Ran Ju, Qianjin Yue, Shisheng Wang   +3 more
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Seismic design of plane steel braced frames using equivalent modal damping ratios

Soil Dynamics and Earthquake Engineering, 2020
Abstract A force-based seismic design method for eccentrically braced and buckling-restrained braced plane steel frames is proposed. The method makes use of equivalent modal damping ratios that play the role of the behavior (strength reduction) factor.
Nicos A. Kalapodis, George A. Papagiannopoulos   +1 more
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Modal truncation, Ritz vectors, and derivatives of closed-loop damping ratios

Journal of Guidance, Control, and Dynamics, 1991
The effect of modal truncation on the damping ratio and their derivatives with respect to an added mass is investigated for a simply supported, multispan beam with a linear quadratic Gaussian control system. It is found that both the damping ratios and derivatives converge slowly, but the derivatives converge more slowly than the damping ratios ...
Chris A. Sandridge, Raphael T. Haftka
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Empirical Modeling of Modal Damping Ratio of Impact-Damped Flexible Beams by GEP

Arabian Journal for Science and Engineering, 2017
In this paper, the empirical models for predicting the modal damping ratio ( $$\xi )$$ of impact-damped flexible beams (IDFB) via gene expression programming (GEP) are proposed. The experimental data used in
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On the modal damping ratios of mixed reinforced concrete – steel buildings

Soil Dynamics and Earthquake Engineering
George A Papagiannopoulos
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Frequencies and damping ratios of bridges through Operational Modal Analysis using smartphones

Construction and Building Materials, 2018
Abstract Seismic Force Assessment in structural design of bridges requires a good estimation of the fundamental period. Estimated periods, using current methodologies in seismic provisions, are approximations that may significantly differ from the real periods.
Sebastián Castellanos-Toro, Mario Marmolejo, Johannio Marulanda, Alejandro Cruz, Peter Thomson   +4 more
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Evaluation of natural periods and modal damping ratios for seismic design of building structures

Earthquake Spectra, 2020
A comprehensive technique for identification of modal properties (i.e. natural periods and equivalent modal damping ratios) of building structures is presented. The proposed identification technique employs a combination of multiple system identification methods; it utilizes the benefits and suppresses the shortcomings of each method to provide a ...
Yijun Xiang, Farzad Naeim, Farzin Zareian   +2 more
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The derivation of modal damping ratios from complex-plane response plots

Journal of Sound and Vibration, 1973
Theoretically derived Kennedy-Pancu type plots for two-degree-of-freedom systems are evaluated to assess the likely accuracy of the determination of natural frequencies and damping ratios from empirical plots. Within the region in which an amplitude/frequency plot alone is inadequate, it is shown that there is a much more restricted region (an ...
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Application of joint time-frequency distribution for estimation of time-varying modal damping ratio

Structural Engineering and Mechanics, 2011
The logarithmic decrement method has been long used to estimate damping ratios in systems with only one modal component such as linear single degree of freedom (SDOF) mechanical systems. This paper presents an application of a methodology that uses joint time-frequency distribution (JTFD) as input, instead of the raw signal, to systems with several ...
H. Bucher, C. Magluta, W.J. Mansur
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Identification of natural frequencies and modal damping ratios from response data

The Journal of the Acoustical Society of America, 1976
Response data are processed in the frequency domain to determine natural frequencies and modal damping ratios of a multidegree-of-freedom system. The excitation can be either deterministic or a random function of time. When the time history of the excitation is now known, the method requires its power spectral density to be flat. An iterative scheme is
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