Improved damping reduction factor models for different response spectra

2021 ◽  
Vol 246 ◽  
pp. 113012
Author(s):  
Tao Liu ◽  
Wenze Wang ◽  
Huakun Wang ◽  
Binjian Su
Keyword(s):  
Response Spectra ◽  
Factor Models ◽  
Reduction Factor ◽  
Damping Reduction Factor ◽  
Different Response

An analytical assessment of elastic and inelastic response spectra

1994 ◽  
Vol 21 (3) ◽  
pp. 386-395 ◽  
Author(s):  
Haluk Sucuoğlu ◽  
Murat Diclelil ◽  
Alphan Nurtuğ
Keyword(s):  
Seismic Design ◽  
Spectral Response ◽  
Seismic Energy ◽  
Response Spectra ◽  
Reduction Factor ◽  
Inelastic Response ◽  
Analytical Assessment ◽  
Damping Reduction Factor ◽  
Earthquake Accelerograms ◽  
Excitation Parameters

A unified assessment of elastic and inelastic response spectra is presented. The effects of various system and excitation parameters on spectral response are investigated. Different spectral forms such as strength spectra, ductility reduction spectra, and damping reduction spectra are employed as graphical tools in the analytical evaluation. The applicability of the expressions for elastic and inelastic response spectra that are employed in seismic design codes is tested by using an ensemble of 21 earthquake accelerograms, all recorded on firm ground along the west coast of North America. New expressions are derived in order to evaluate the coupled effects of damping and ductility ratios on inelastic response spectra. Key words: elastic and inelastic response spectra, damping reduction factor, ductility reduction factor, seismic energy dissipation, strength ratio, mean plus one standard deviation.

scholarly journals Odor coding in the antenna of the tsetse flyGlossina morsitans

2019 ◽  
Vol 116 (28) ◽  
pp. 14300-14308 ◽  
Author(s):  
Neeraj Soni ◽  
J. Sebastian Chahda ◽  
John R. Carlson
Keyword(s):  
Functional Organization ◽  
Response Spectra ◽  
Fruit Fly ◽  
Morphological Type ◽  
Tsetse Fly ◽  
Sub Saharan Africa ◽  
Tsetse Flies ◽  
Response Dynamics ◽  
Olfactory Sensilla ◽  
Different Response

Tsetse flies transmit trypanosomiasis to humans and livestock across much of sub-Saharan Africa. Tsetse are attracted by olfactory cues emanating from their hosts. However, remarkably little is known about the cellular basis of olfaction in tsetse. We have carried out a systematic physiological analysis of theGlossina morsitansantenna. We identify 7 functional classes of olfactory sensilla that respond to human or animal odorants, CO2, sex and alarm pheromones, or other odorants known to attract or repel tsetse. Sensilla differ in their response spectra, show both excitatory and inhibitory responses, and exhibit different response dynamics to different odor stimuli. We find striking differences between the functional organization of the tsetse fly antenna and that of the fruit flyDrosophila melanogaster. One morphological type of sensilla has a different function in the 2 species: Trichoid sensilla respond to pheromones inDrosophilabut respond to a wide diversity of compounds inG. morsitans.In contrast toDrosophila, all testedG. morsitanssensilla that show excitatory responses are excited by one odorant, 1-octen-3-ol, which is contained in host emanations. The response profiles of some classes of sensilla are distinct but strongly correlated, unlike the organization described in theDrosophilaantenna. Taken together, this study defines elements that likely mediate the attraction of tsetse to its hosts and that might be manipulated as a means of controlling the fly and the diseases it transmits.

Application of inelastic response spectra derived from seismic hazard spectral ordinates for Canada

1996 ◽  
Vol 23 (5) ◽  
pp. 1051-1063 ◽  
Author(s):  
J. L. Humar ◽  
M. A. Rahgozar
Keyword(s):  
Seismic Hazard ◽  
Response Spectra ◽  
Reduction Factor ◽  
Reliable Estimate ◽  
Spectral Acceleration ◽  
Hazard Maps ◽  
Uniform Hazard Spectra ◽  
Spectral Curves ◽  
Modification Factor ◽  
Recorded Data

The Geological Survey of Canada is currently producing a suite of new hazard maps for Canada. These maps take into account the additional recorded data obtained during the past 13 years, as well as the new geological and tectonic information that has recently become available. They provide elastic spectral acceleration values for a uniform probability of exceedance of 10% in 50 years. A method of using the uniform hazard spectral values to obtain design response spectral curves for different values of ductility is presented here. The method uses two spectral values obtained from the hazard maps, the peak spectral acceleration for the site and the spectral acceleration corresponding to a period of 0.5 s. Empirical expressions are developed to represent the design response spectra. It is shown that by using inelastic spectral accelerations rather than the elastic spectral values in association with a reduction factor, the new method provides a more reliable estimate of the design forces. Key words: uniform hazard spectra; inelastic spectra, seismic design forces, force modification factor, foundation factor, seismic hazard for Canada.

Yield Strength Reduction Factor of Nonlinear SDOF Systems on the Supporting Structures

2016 ◽  
Author(s):  
Ichiro Tamura ◽  
Shinichi Matsuura ◽  
Ryuya Shimazu
Keyword(s):  
Yield Strength ◽  
Inelastic Deformation ◽  
Response Spectra ◽  
Reduction Factor ◽  
Strength Reduction ◽  
Inelastic Behavior ◽  
Strength Reduction Factor ◽  
Supporting Structure ◽  
Floor Response Spectra ◽  
Supporting Structures

Equipment installed on the supporting structure responds to the earthquake floor motion, which is strongly amplified by the structural response of the supporting structure. The required yield strength of equipment can be reduced by allowing inelastic deformation of the supporting structure and its equipment. Inelastic behavior of the supporting structure can significantly reduce elastic floor response spectra, especially their peak values. Furthermore, the allowance of inelastic deformation of equipment in strongly amplified spectral region produces a significant reduction in the required yield strength of equipment. In this study, we discussed inelastic behavior of single-degree-of-freedom(SDOF) systems installed on the supporting structures by using constant-ductility floor response spectra. Constant-ductility floor response spectra readily provide the yield strength of a SDOF system necessary to limit the ductility demand imposed by an earthquake floor motion to a specified value. Based on these discussions, we propose simple and conservative equations of the yield strength reduction factor of nonlinear inelastic SDOF systems with the natural period, the ductility factor and the stiffness ratio for earthquake floor motions.

Research on Inelastic Response Spectra for Asymmetric Plan Systems Subjected to Bi-Directional Earthquake Motions

2012 ◽  
Vol 166-169 ◽  
pp. 2332-2336
Author(s):  
Feng Wang ◽  
Hong Nan Li ◽  
Ting Hua Yi
Keyword(s):  
Soft Soil ◽  
Rotation Frequency ◽  
Response Spectra ◽  
Reduction Factor ◽  
Strength Reduction ◽  
Strength Reduction Factor ◽  
Inelastic Response ◽  
Surface Plasticity ◽  
Soil Site ◽  
Spectral Equation

The limitations of traditional inelastic response spectra are discussed. Considering a one-storey asymmetric plan system subjected to perpendicular bi-directional earthquake motions, the inelastic multi-dimensional strength reduction factor spectra is presented. The yield rule of the asymmetric plan system is determined by two-dimensional yield-surface plasticity function. The spectral equation is simplified by the relationship of strength reduction factors between x-direction and y-direction.The multi-dimensional spectra are analyzed based on 30 pair strong earthquake motion records for hard soil site, intermediate soil site and soft soil site. Analytic results shows that the strength reduction factor mean spectra for each soil site has its own characteristics, and the strength reduction factor spectra is affected strongly by ductility, normalized stiffness eccentricity, period and rotation frequency ratio.

Effects of Excitation Bandwidth on Damping Reduction Factor

2018 ◽  
pp. 1-28 ◽  
Author(s):  
Rita Greco ◽  
Alessandra Fiore ◽  
Giuseppe Carlo Marano ◽  
Bruno Briseghella
Keyword(s):  
Reduction Factor ◽  
Damping Reduction Factor

Influence of Ground Motion Duration on Damping Reduction Factor

2014 ◽  
Vol 18 (5) ◽  
pp. 816-830 ◽  
Author(s):  
Jing Zhou ◽  
Kai Tang ◽  
Huiying Wang ◽  
Xiandan Fang
Keyword(s):  
Ground Motion ◽  
Reduction Factor ◽  
Damping Reduction Factor
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