Development of elasto-plastic viscous damper finite element model for reinforced concrete frames     

《Soil Dynamics and Earthquake Engineering》2014

By advancing the technologies regarding seismic control of structures and development of earthquake resistance systems in the past decades application of different types of earthquake energy dissipation system has incredibly increased. Viscous damper device as a famous and the simplest earthquake energy dissipation system is implemented in many new structures and numerous number of researches have been done on the performance of viscous dampers in structures subjected to earthquake. The experience of recent severe earthquakes indicates that sometimes the earthquake energy dissipation devices are damaged during earthquakes and there is no function for structural control system. So, damage of earthquake energy dissipation systems such as viscous damper device must be considered during design of earthquake resistance structures.This paper demonstrates the development of three-dimensional elasto-plastic viscous damper element consisting of elastic damper in the middle part and two plastic hinges at both ends of the element which are compatible with the constitutive model to reinforce concrete structures and are capable to detect failure and damage in viscous damper device connections during earthquake excitation. The finite element model consists of reinforced concrete frame element and viscous damper element is developed and special finite element algorithm using Newmark׳s direct step-by-step integration is developed for inelastic dynamic analysis of structure with supplementary elasto-plastic viscous damper element. So based on all the developed components an especial finite computer program has been codified for “Nonlinear Analysis of Reinforced Concrete Buildings with Earthquake Energy Dissipation System”. The evaluation of seismic response of structure and damage detection in structural members and damper device was carried out by 3D modeling, of 3 story reinforced concrete frame building under earthquake multi-support excitation.  相似文献   

地震大小的度量     

陈章立  陈翰林  赵翠萍  王勤彩  华卫  周连庆 《中国地震研究》2014,28(3):285-298

The paper begins with a brief review of the research history of earthquake size measurement. On this basis, the author pointed out the following points： ① In recent decades, ML, mb （mH ）, Ms magnitude scales are widely used as measures of earthquake size. However, these magnitude scales have a deficiency of ＂overgeneralization＂ and ＂magnitude saturation＂. Moreover, since they do not fully take into account the regional difference of seismic attenuation, especially the difference of site effects on the amplification of ground motion, these magnitude scales are but inaccurate measures of earthquake size. ② Seismic moment M0 not only has clear physical meaning, but also overcomes the deficiencies existing in ML, mb （mB ） and Ms magnitude scales, so it is the most suitable physical quantity for measuring earthquake size scientifically. In order to continue to use the term ＂magnitude＂, Kanamori defined the moment magnitude scale Act. Although its prerequisite assumptions remain to be studied, it is still a reasonable scale used as a measure of the relative size of an earthquake. ③ For measuring the earthquake size more scientifically, we must make full use of a large amount of waveform data from modern regional digital seismograph networks, strengthen the research on seismic wave attenuation characteristics, site effect, calculation of source parameters and the related scaling relations. In improving the measurement methods for ML, mb （mB ） and Ms magnitude, we should focus on the improvement of Mw scale and carry forward the work as gradually taking Mw magnitude scale as the uniform physical quantity to measure the relative size of earthquakes, so as to lay a more solid foundation for research in earthquake science and earthquake prediction.  相似文献   

Risk formulation for the sonic effects of offshore wind farms on fish in the EU region   总被引：1，自引：0，他引：1  

Ryunosuke Kikuchi 《Marine pollution bulletin》2010,60(2):172-177

In 2007, European leaders agreed to source 20% of their energy needs from renewable energy; since that time, offshore wind farms have been receiving attention in the European Union (EU). In 2008, the European Community submitted a proposal to the United Nations Environment Program (UNEP) in order to combat marine noise pollution. In consideration of these facts, the present paper aims to deduce a preliminary hypothesis and its formulation for the effect of offshore wind farm noise on fish. The following general picture is drawn: the short-term potential impact during pre-construction; the short-term intensive impact during construction; and the physiological and/or masking effects that may occur over a long period while the wind farm is in operation. The EU’s proposal to UNEP includes noise databases that list the origins of man-made sounds; it is advisable that offshore wind farms should be listed in the noise databases in order to promote rational environment management.  相似文献   

Optimization and Modeling of Biogas Production From Green Waste/Biowaste Co‐Digestion Using Leachate and Sludge          下载免费PDF全文

Arwa Abdelhay  Abeer Albsoul  Fatimeh Hadidi  Abeer Abuothman 《洁净——土壤、空气、水》2016,44(11):1557-1563

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中国化石能源使用可持续性评估——基于1990～2006年数据   总被引：2，自引：0，他引：2  

赵震宇  宋冬林 《地理科学》2010,(1)

进入1990年代,中国经济走上了前所未有的快速增长轨道,而化石能源作为推动经济增长的最主要动力源泉却同时也是造成环境恶化的双刃剑。采用加拿大生态经济学家Ree和Wackernagel共同发展的生态足迹模型,对1990～2006中国化石能源使用的生态足迹和生态承载力进行了计算,得到了该时期中国化石能源使用已处于生态赤字状态的评估结果。而化石能源使用过程中单位能源的CO2排量没有得到显著改善和森林覆盖率没有明显的增长是造成该时期中国化石能源使用处于生态赤字状态的主要原因。  相似文献   

基于WebGIS的地震复发周期与危险性分析     

刘云华  单新建  李卫东  马照松  张国宏 《地震》2010,30(4):58-64

根据地震复发周期模型, 利用现有的地质构造等资料把南北地震带划分为若干相对独立的活动构造区, 对能量积累阶段及地震危险性的预测建立相应的数学模型, 并构建基于WebGIS的网络计算平台, 由客户端任意在研究区选择构造分区, 并输入所选构造分区相应的计算参数, 提交到集群服务器计算模型进行计算, 对所选构造分区的地震危险性阶段及潜在震级进行预测并把结果以WebGIS方式返回给客户端。 实现了利用远程计算技术与并行算法对活动断裂能量积累与释放过程的模拟计算, 其结果可以为判定地震中短期预测的地点和震级提供依据。  相似文献   

Seasonal variations in internal wave energy in a Scottish sea loch     

F. Cottier  M. Inall  C. Griffiths 《Ocean Dynamics》2004,54(3-4):340-347

Near-continuous observations of an internal wave field were made over a period of 13 months at a location in Inchmarnock Water at the northern end of the Clyde Sea. This paper sets out to determine the seasonal form of the energy density of the internal wave field at this location based on the hypothesis that it varies smoothly throughout the year, being greater in summer than in winter. The mooring was maintained between June 1999 and July 2000 in 150-m water with seven deployments. Estimates of kinetic and potential energy density were derived from Acoustic Doppler Current Profiler (ADCP) and vertical temperature profiles respectively. Both were shown to vary on time scales less than 1 month with median values of mean kinetic energy (KE) density0.5 J m^–3 and for mean potential energy (PE) density0.01 J m^–3. The energy of the internal wave field was found to be continuous and without a clear seasonal form. Further, it was also always non-zero with intermittent peaks of much higher energy. In the late autumn the system experienced complete vertical overturning driven by local convective processes destroying the thermocline and causing a reduction in the overall KE density.Responsible Editor: Jens KappeubergOrginally presented as a poster at PECS 2002, Hamburg Germany  相似文献   

Water use by intensively cultivated willow using estimated stomatal parameter values     

Harald Grip  Sven Halldin  Anders Lindroth 《水文研究》1989,3(1):51-63

Large land areas in Sweden are planned to be planted with high producing, short rotation forest stands of willow in the beginning of the 1990s. Since willow is a highly hydrophilic species, this new land use may have strong implications on water resources. To assess these implications, evaporation of Salix viminalis and Salix viminalis x caprea stands in lysimeters was analysed with the simple, yet physically realistic KAUSHA model. Parameter values for the Lohammar equation were deduced (b = 100 m³ kg^?1, k_max = 0.01 m s^?1), believed to be applicable to other sites. Simulated evaporation during the 1980 growth season for a normal stand with a production of 12 tonnes of dry matter per hectare per season was 526 mm, of which 375 mm was transpiration, 56 mm interception evaporation, and 95 mm soil evaporation. For an optimally irrigated 20-tonnes stand, the total evaporation was 584 mm, of which 430 mm was transpiration. As a comparison, Penman open water evaporation was 430 mm. To avoid soil water stress in the 20-tonnes stand, 140 mm was needed as irrigation, equivalent to 25 per cent of the mean annual precipitation. Since intensively cultivated willow plantations seemed to be using much water, it was concluded that introduction of this agri-forestry practice must be carefully planned to make use of this property, e.g. in biological filters or in reclaiming water-logged land.  相似文献   

天津市夜间城市热岛的数值模拟   总被引：7，自引：0，他引：7  

边海  铁学熙 《地理学报》1988,(2)

本文基于Myrap等人的工作,提出了一个能量平衡模式,并用实测的天津市夜间近地面温度场对模式进行了验证.应用这个模式,可给出天津市近地面热岛的适当预报,同时,可对天津市夜间城市热岛中各能量通量的空间变化进行讨论.  相似文献   

空气节能器研制与应用     

唐文模  洪祥炎  张家良  杨迪寰 《广东海洋大学学报》1990,(1)

本文针对渔船使用增压柴油机中存在的极待解决的问题,提出了增设空冷节能器的必要性,并设计研制出了空冷节能器。试验结果表明,该空冷节能器节油率达8%,总排温降低70～100℃,增加功率20%,压力损失△P_K<160mmH_2O。  相似文献