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1.
Experimental study of deformable connection consisting of buckling‐restrained brace and rubber bearings to connect floor system to lateral force resisting system 下载免费PDF全文
Georgios Tsampras Richard Sause Robert B. Fleischman Jose I. Restrepo 《地震工程与结构动力学》2017,46(8):1287-1305
This paper presents experimental and numerical studies of a full‐scale deformable connection used to connect the floor system of the flexible gravity load resisting system to the stiff lateral force resisting system (LFRS) of an earthquake‐resistant building. The purpose of the deformable connection is to limit the earthquake‐induced horizontal inertia force transferred from the floor system to the LFRS and, thereby, to reduce the horizontal floor accelerations and the forces in the LFRS. The deformable connection that was studied consists of a buckling‐restrained brace (BRB) and steel‐reinforced laminated low‐damping rubber bearings (RB). The test results show that the force–deformation responses of the connection are stable, and the dynamic force responses are larger than the quasi‐static force responses. The BRB+RB force–deformation response depends mainly on the BRB response. A detailed discussion of the BRB experimental force–deformation response is presented. The experimental results show that the maximum plastic deformation range controls the isotropic hardening of the BRB. The hardened BRB force–deformation responses are used to calculate the overstrength adjustment factors. Details and limitations of a validated, accurate model for the connection force–deformation response are presented. Numerical simulation results for a 12‐story reinforced concrete wall building with deformable connections show the effects of including the RB in the deformable connection and the effect of modeling the BRB isotropic hardening on the building seismic response. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
2.
Ioannis A. Daglis Georgios Balasis Natalia Ganushkina Fiori-Anastasia Metallinou Minna Palmroth Risto Pirjola Ioanna Tsagouri 《Acta Geophysica》2009,57(1):141-157
Comprehensive understanding of the dynamics of the coupled solar wind-magnetosphere-ionosphere system is of utmost interest,
both from the perspective of solar system astrophysics and geophysics research and from the perspective of space applications.
The physical processes involved in the dynamical evolution of this complex coupled system are pertinent not only for the Sun-Earth
connection, but also for major phenomena in other astrophysical systems. Furthermore, the conditions in geospace collectively
termed space weather affect the ever increasing technological assets of mankind in space and therefore need to be understood,
quantified and efficiently forecasted. The present collaborative paper communicates recent advances in geospace dynamic coupling
research through modeling, simulations and data analysis and discusses future directions. 相似文献
3.
Birmpilis Georgios Hall Stephen A. Lages Sebastian Dijkstra Jelke 《Acta Geotechnica》2019,14(6):1965-1975
Acta Geotechnica - This paper introduces a new experimental method to monitor the evolving intra-particle, nanometre-scale response during hydro-mechanical tests on undisturbed wet clay samples... 相似文献
4.
Midlittoral polychaete communities in the Eastern Mediterranean Sea: new information from the implementation of the Natural Geography in Shore Areas (NaGISA) protocol and comparisons at local and regional scales 下载免费PDF全文
Georgios Chatzigeorgiou Kleoniki Keklikoglou Sarah Faulwetter Fabio Badalamenti Miltiadis‐Spyridon Kitsos Christos Arvanitidis 《Marine Ecology》2017,38(1)
The aim of this study was to attempt to fill current knowledge gaps on midlittoral Mediterranean biodiversity at local and regional scales, by using benthic polychaetes as a model taxon. Two different data sets were analysed: (i) a quantitative data set from the two Natural Geography in Shore Areas (NaGISA) study sites in Crete and (ii) a qualitative data set from multiple sites across the Mediterranean. At the local scale, the results provide evidence that (i) discrete species communities are formed in midlittoral Mediterranean habitats, which vary by geographical location and year, depending on the scale of observation; (ii) macrophyte coverage and Chl‐a are the only environmental variables associated, albeit weakly, with the above pattern; (iii) although naturally disturbed, the Cretan NaGISA sites do not seem to experience any anthropogenic stress; (iv) environmental heterogeneity and history seem to be much less important in shaping the polychaete communities than inter‐specific interactions; however, it is not possible to specify at this stage whether local or regional processes or even their interactions may shape the polychaete communities. At the regional scale, the results indicate that (i) the only factor that seems to be involved in the regional pattern is the identity of the study providing the data sets, which implies variability and bias in how research projects are carried out, from the sampling design through to data collection and analysis; (ii) the Cretan NaGISA sites may be considered as representative of the habitat in the Mediterranean, under certain conditions. 相似文献
5.
Development of a seismic damage and loss scenario for contemporary and historical buildings in Thessaloniki, Greece 总被引:3,自引:0,他引:3
Andreas J. Kappos Georgios Panagopoulos Gregorios G. Penelis 《Soil Dynamics and Earthquake Engineering》2008,28(10-11):836
The methodologies used in Greece for estimating direct losses in both reinforced concrete (R/C) and masonry buildings (also including monuments) are summarised, the critical issue of data collection is addressed, and practical solutions that have been tried are discussed. The development of a seismic risk scenario for contemporary and historical buildings in Thessaloniki is then presented and some key results are given, including the expected geographical distribution of building damage (due to the scenario earthquake) in the municipality of Thessaloniki; damage is described both in structural and in economic terms. 相似文献
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Development and validation of a novel-based combination operational air quality forecasting system in Greece 总被引:1,自引:1,他引:0
Stamatis Zoras Vasilios Evagelopoulos Ioannis Pytharoulis Georgios Kallos 《Meteorology and Atmospheric Physics》2010,106(3-4):127-133
In the present work, a model combination is developed in order to provide the public, in north-western Greece, with the next day air quality forecast. Generally, the development and deployment of a real-time numerical air quality prediction system is technically challenging while even more in complex terrain. The Air Pollution Model (TAPM) (http://www.cmar.csiro.au/research/tapm) is a hydrostatic prognostic mesoscale model. It has been calibrated for the area in recent studies and used in air quality assessments. In 2007, TAPM has started operating in a real-time operational mode for the prediction of next day’s weather forecast, particulate matter (PM10 with an aerodynamic diameter <10 μm) daily average concentration and Air Pollution Indexes. The model setup is a link up between TAPM and SKIRON modeling system (http://forecast.uoa.gr). 相似文献
9.
George Contopoulos Mirella Harsoula Georgios Lukes-Gerakopoulos 《Celestial Mechanics and Dynamical Astronomy》2012,113(3):255-278
We study the periodic orbits and the escapes in two different dynamical systems, namely (1) a classical system of two coupled oscillators, and (2) the Manko-Novikov metric which is a perturbation of the Kerr metric (a general relativistic system). We find their simple periodic orbits, their characteristics and their stability. Then we find their ordered and chaotic domains. As the energy goes beyond the escape energy, most chaotic orbits escape. In the first case we consider escapes to infinity, while in the second case we emphasize escapes to the central ??bumpy?? black hole. When the energy reaches its escape value, a particular family of periodic orbits reaches an infinite period and then the family disappears (the orbit escapes). As this family approaches termination it undergoes an infinity of equal period and double period bifurcations at transitions from stability to instability and vice versa. The bifurcating families continue to exist beyond the escape energy. We study the forms of the phase space for various energies, and the statistics of the chaotic and escaping orbits. The proportion of these orbits increases abruptly as the energy goes beyond the escape energy. 相似文献
10.
George MillwardSteve Miller Tom StallardAlan D. Aylward Nicholas Achilleos 《Icarus》2002,160(1):95-107
Recent work has been concerned with calculating the three-dimensional ion concentrations and Pedersen and Hall conductivities within the auroral region of Jupiter for varying conditions of incident electron precipitation. Using the jovian ionospheric model, we present results that show the auroral ionospheric response to changing the incoming flux of precipitating electrons (for constant initial energy) and also the response to changing the initial energy (for both constant flux and constant energy flux). The results show that, for expected energy fluxes of precipitating particles, the average auroral integrated Pedersen conductivity attains values in excess of 1 mho. In addition, it is shown that electrons with an initial energy of around 60 keV are particularly effective at generating auroral conductivity: Particles of this energy penetrate most effectively to the layer of the jovian ionosphere at which the auroral conductivity is at a maximum. 相似文献