Elasto-Plastic Dynamic Responses Analysis of Double-Layer Spherical Lattice Shells under Multiple Earthquake Excitations

Based on the large geometric deformation and nonlinear of material theories, the seismic responses of a double-layer spherical lattice shells structure were studied. The results show that under multi-dimensional earthquake, the maximum displacement and axial stress, as well as plastic ratio of the structure will be obviously increased than those corresponding to the responses under single-dimensional earthquake. When long-period seismic wave was taken as the input wave, the responses of the structure were the maximum.

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Seismic wave energy inferred from long-period body wave inversion

Bulletin of the Seismological Society of America ◽

10.1785/bssa0780051707 ◽

1988 ◽

Vol 78 (5) ◽

pp. 1707-1724

Author(s):

Masayuki Kikuchi ◽

Yoshio Fukao

Keyword(s):

Seismic Wave ◽

Wave Energy ◽

Body Wave ◽

Empirical Relation ◽

P Waves ◽

Average Value ◽

Long Period ◽

Wave Inversion ◽

Moment Ratio ◽

Order Of Magnitude

Abstract The seismic wave energy is evaluated for 35 large earthquakes by inverting far-field long-period P waves into the multiple-shock sequence. The results show that the seismic wave energy thus obtained is systematically less than that inferred from the Gutenberg-Richter's formula with the seismic magnitude. The difference amounts to one order of magnitude. The results also show that the energy-moment ratio is well confined to a narrow range: 10−6 < ES/Mo < 10−5 with the average of ∼5 × 10−6. This average value is exactly one order of magnitude as small as the energy-moment ratio inferred from the Gutenberg-Richter's formula using the moment magnitude. Comparing the energy-moment ratio with Δσo/2μ, where Δσo and μ are the stress drop and the rigidity, we obtain an empirical relation: ES/Mo ∼ 0.1 × Δσ0/2μ. Such a relation can be interpreted in terms of a subsonic rupture where the energy loss due to cohesion is not negligible to the seismic wave energy.

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Mode Transition and Refractive Index Response in Long-Period Fiber Grating Coated with Double-Layer Overlays Including Metal Film

Acta Optica Sinica ◽

10.3788/aos201434.0406005 ◽

2014 ◽

Vol 34 (4) ◽

pp. 0406005

Author(s):

顾铮天 Gu Zhengtian ◽

蓝锦龙 Lan Jinlong

Keyword(s):

Refractive Index ◽

Double Layer ◽

Metal Film ◽

Fiber Grating ◽

Mode Transition ◽

Long Period Fiber Grating ◽

Long Period ◽

Period Fiber Grating

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Quasi-Static Characteristics and Vibration Responses Analysis of Helical Geared Rotor System with Random Cumulative Pitch Deviations

Applied Sciences ◽

10.3390/app10124403 ◽

2020 ◽

Vol 10 (12) ◽

pp. 4403

Author(s):

Bing Yuan ◽

Geng Liu ◽

Lan Liu

Keyword(s):

Degrees Of Freedom ◽

Transmission Error ◽

Rotor System ◽

Dynamic Responses ◽

Contact Ratio ◽

Tooth Contact Analysis ◽

Long Period ◽

Light Load ◽

Vibration Responses ◽

Loaded Tooth Contact Analysis

As one of the long period gear errors, the effects of random cumulative pitch deviations on mesh excitations and vibration responses of a helical geared rotor system (HGRS) are investigated. The long-period mesh stiffness (LPMS), static transmission error (STE), as well as composite mesh error (CMS), and load distributions of helical gears are calculated using an enhanced loaded tooth contact analysis (LTCA) model. A dynamic model with multi degrees of freedom (DOF) is employed to predict the vibration responses of HGRS. Mesh excitations and vibration responses analysis of unmodified HGRS are conducted in consideration of random cumulative pitch deviations. The results indicate that random cumulative pitch deviations have significant effects on mesh excitations and vibration responses of HGRS. The curve shapes of STE and CMS become irregular when the random characteristic of cumulative pitch deviations is considered, and the appearance of partial contact loss in some mesh cycles leads to decreased LPMS when load torque is relatively low. Vibration modulation phenomenon can be observed in dynamic responses of HGRS. In relatively light load conditions, the amplitudes of sideband frequencies become larger than that of mesh frequency and its harmonics (MFIHs) because of relatively high contact ratio. The influences of random cumulative pitch deviations on the vibration responses of modified HGRS are also discussed.

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Measuring the diffuse‐double layer at an electrochemical interface with long period X‐ray standing waves

Synchrotron Radiation News ◽

10.1080/08940889008602582 ◽

1990 ◽

Vol 3 (5) ◽

pp. 25-29 ◽

Cited By ~ 4

Author(s):

Michael J. Bedzyk

Keyword(s):

Double Layer ◽

Standing Waves ◽

Diffuse Double Layer ◽

X Ray ◽

Long Period ◽

Electrochemical Interface

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An Artificial Seismic Wave Suitable for Suspended Converter Valve in the UHVDC Transmission Project

E3S Web of Conferences ◽

10.1051/e3sconf/201911802039 ◽

2019 ◽

Vol 118 ◽

pp. 02039

Author(s):

Jin Xiao ◽

Mingduo Huang ◽

Qiguo Sun

Keyword(s):

Finite Element ◽

Seismic Wave ◽

Seismic Design ◽

Response Spectrum ◽

Time History ◽

Element Model ◽

Series Method ◽

Long Period ◽

Standard Response ◽

The Finite Element Model

The finite element model of suspended converter valve in an UHVDC transmission project with characteristics of flexible is constructed, and its vibration characteristics are simulated and analyzed firstly. The results show that this kind of suspended converter valve has obvious long-period character. Secondly, the long period phase of standard response spectrum in Code for Seismic Design of Buildings (GB50011-2010) is modified, and then the artificial seismic wave is synthesized employing the triangular series method. The result shows that this artificial seismic wave has long-period character. Finally, the time-history seismic dynamic simulation of the converter valve is done, and the seismic responses of the converter valve excited by three kinds of seismic wave with different period characters are compared and analyzed. The results show that the swing and stress of the suspended converter valve are larger under the long-period seismic wave synthesized in this paper. The quasi-resonance damage caused by long-period seismic wave should be concerned specially in the actual UHVDC transmission project.

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Dynamic Response of a Steel Bridge under Earthquake Action in Liugong Island of Weihai

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.777.23 ◽

2015 ◽

Vol 777 ◽

pp. 23-26

Author(s):

Xing Zi Jiao ◽

Yong Bo Shao

Keyword(s):

Dynamic Response ◽

Seismic Wave ◽

Maximum Stress ◽

Seismic Action ◽

Steel Bridge ◽

Maximum Displacement ◽

Special Steel ◽

Dynamic Analyses ◽

Earthquake Action ◽

Bracing System

This study presents finite element analyses for a special steel bridge under the action an actual seismic wave. The maximum stress and the maximum deflection of the bridge are calculated based on the dynamic analyses. It is found that the bracing system and the beams between the two columns at the end of the bracing system are the critical members in the steel bridge under seismic action. The maximum displacement of the steel bridge is located at the overhang beams at the bridge end. However, the dynamic response is different when the seismic wave is input in different directions. Based on the numerical results, it is found that the special steel bridge is safe under the seismic action.

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