Results 181 to 190 of about 2,652 (218)

Magnetic Perturbations Excited by Seismic Waves

Physica Scripta, 2001
Magnetic field perturbations on the Earth's surface and in the ionosphere excited by atmospheric acoustic waves have been investigated. The mechanism of the excitation consists of the growth of the atmospheric acoustic waves, caused by an earthquake, carried upwards and exciting Alfven and fast magnetosonic waves in the ionosphere.
S V Koshevaya, V V Grimalsky, G N Burlak, R Pérez Enríquez, A N Kotsarenko   +4 more
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Maximum Structural Response to Seismic Excitations

Journal of the Engineering Mechanics Division, 1970
A method is presented by which a least favorable structural response can be estimated to the excitation of nondeterministic nature such as earthquake acceleration. Under the assumption that a fair amount of information on the modulus of the Fourier transform of the excitation makes it possible to select an envelope of the modulus, the present approach ...
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Excitation of seiches in channels by seismic waves

Deep Sea Research and Oceanographic Abstracts, 1965
Description of seiches which occurred along the Gulf Coast of the United States and in Norway at the times of the Alaskan earthquake of 1964 and the Assam earthquake of 1950 are reviewed. An analytical expression is derived for the effect of seismic surface waves on a water channel of width L and depth H.
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Spatial Seismic Excitations and Response Spectra

Journal of Engineering Mechanics, 1993
A random‐vibration‐based force‐response spectrum of a simple oscillating frame is proposed as a simplified measure of the effect of spatial seismic excitations on structures. Such a response spectrum reflects the effect of incoherent support motions on quasi‐static and dynamic response of structures.
Zbigniew Zembaty, Steen Krenk
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Active Control of Seismic‐Excited Buildings

Journal of Structural Engineering, 1985
An investigation is made of the possible application of both the active tendon and active mass damper control systems to buildings excited by strong earthquakes. The effectiveness of both active control systems as measured by the reduction of coupled lateral-torsional motions of buildings is studied.
B. Samali, J. N. Yang, S. C. Liu
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Identification of structures subject to unknown seismic excitation

2002
Giulianova ...
CAPECCHI, Danilo, DE ANGELIS, Maurizio, V. SEPE   +2 more
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SPATIAL SEISMIC EXCITATIONS AND RESPONSE SPECTRA

ISET Journal of Earthquake Technology, 2007
Formal extensions of the response spectrum method to include spatial seismic effects are reviewed. Two approaches are described in detail: the first based on random vibrations of a simple oscillator under two-component excitations, and the second analyzing multi-column building seismic response.
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Active vibration control of seismic excitation

Nonlinear Dynamics, 2017
Seismic wave control is very important both in civil and mechanical engineering. Common passive methods for isolating a building or a device include base isolators and tuned mass dampers. In the present paper, a time-varying controllable spring is considered as a vibration isolator for a linear mechanical system.
Barbieri, Marco, Ilanko, Sinniah, Pellicano, Francesco   +2 more
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Structural Responses Due to Seismic Excitations

2014
The determination of the earthquake ground motions is an essential part of earthquake engineering. However, as the rate and duration of energy released from earthquakes is relatively random, it is not possible to obtain the exact excitation to which the structure will be subjected.
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On the excitation of the earth's seismic normal modes

pure and applied geophysics, 1976
The excitation of the earth's normal modes is formulated as an initial value problem. The static state of the earth, stressed from its hydrostatic reference situation, is considered as the initial state. The initial state is relaxed, at the time of the earthquake, by the removal of the forces maintaining the departure from hydrostatic equilibrium ...
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