American Society of Civil Engineers

Nonstationary Random Critical Seismic Excitations

by R. N. Iyengar, (Assoc. Prof., Dept. of Civ. Engrg., Indian Inst. of Sci., Bangalore 560 012, India) and C. S. Manohar, (Research Scholar, Dept. of Civ. Engrg., Indian Inst. of Sci., Bangalore, India)

Journal of Engineering Mechanics, Vol. 113, No. 4, April 1987, pp. 529-541, (doi:

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Document type: Journal Paper
Abstract: A method is presented to find nonstationary random seismic excitations with a constraint on mean square value such that the response variance of a given linear system is maximized. It is also possible to incorporate the dominant input frequency into the analysis. The excitation is taken to be the product of a deterministic enveloping function and a zero mean Gaussian stationary random process. The power spectral density function of this process is determined such that the response variance is maximized. Numerical results are presented for a single-degree system and an earth embankment modeled as shear beam.

ASCE Subject Headings:
Earth-fill dams
Earthquake engineering
Linear systems
Power spectral density
Random processes