A Constrained Optimal Rayleigh Damping Coefficients for Structures with Closely Spaced Natural Frequencies in Seismic Analysis
A constrained optimization method is proposed to determine Rayleigh damping coefficients for the accurate analysis of complex structures. To this end, an objective function was defined to be a complete quadratic combination of the modal errors of a peak base reaction evaluated by response spectral analysis. An optimization constraint was enforced to make the damping ratio of a prominent contribution mode exact. Parametric studies were conducted to investigate the effects of the constraint, the cross term of modes, and weighting factors on the optimization objective. A two-story building and a real-world lattice structure were analyzed under six earthquake ground motions to understand the characteristics and demonstrate the accuracy and effectiveness of the proposed optimization method. Unlike the conventional Rayleigh damping, the optimization method provided an optimal load-dependent reference frequencies that account for varying frequency characteristics of earthquakes around the prominent contribution mode.
D. Pan et al., "A Constrained Optimal Rayleigh Damping Coefficients for Structures with Closely Spaced Natural Frequencies in Seismic Analysis," Advances in Structural Engineering, vol. 20, no. 1, pp. 81-95, SAGE Publications Inc., Jan 2017.
The definitive version is available at http://dx.doi.org/10.1177/1369433216646007
Civil, Architectural and Environmental Engineering
Keywords and Phrases
Complete Quadratic Combination; Constrained Optimal Solution; Rayleigh Damping; Seismic Response Analysis; Damping; Earthquakes; Geophysics; Seismology; Spectrum Analysis; Earthquake Ground Motions; Frequency Characteristic; Reference Frequency
International Standard Serial Number (ISSN)
Article - Journal
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