Optimal design of passive energy dissipation systems based on H∞ and H2 performances     

J. N. Yang  S. Lin  J‐H. Kim  A. K. Agrawal 《地震工程与结构动力学》2002,31(4):921-936

Passive energy dissipation devices (EDDs), such as viscous dampers, viscoelastic dampers, etc., have been used to effectively reduce the dynamic response of civil infrastructures, such as buildings and bridges, subject to earthquakes and strong winds. The design of these passive energy dissipation devices (EDDs) involves the determination of the optimal locations and the corresponding capacities. In this paper, we present two optimal design methodologies for passive EDDs based on active control theories, including H_∞ and H₂ performances, respectively. The optimal design methodologies presented are capable of determining the optimal locations and the corresponding capacities of EDDs. Emphasis is placed on the application of linear matrix inequality (LMI) for the effective design of passive EDDs using the popular MATLAB toolboxes. One important advantage of the proposed approaches is that the computation of the structural response is not needed in the design process. The proposed optimal design methodologies have been applied to: (i) a 10‐storey building and a 24‐storey building both subject to earthquake excitations, and (ii) a 76‐storey wind‐excited benchmark building, to demonstrate the advantages of the proposed design methodologies over the conventional equal capacity design. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

Study on effects of damping in laminated rubber bearings on seismic responses for a ⅛ scale isolated test structure     

Bong Yoo  Yang‐Hann Kim 《地震工程与结构动力学》2002,31(10):1777-1792

The effects of damping in various laminated rubber bearings (LRB) on the seismic response of a ?‐scale isolated test structure are investigated by shaking table tests and seismic response analyses. A series of shaking table tests of the structure were performed for a fixed base design and for a base isolation design. Two different types of LRB were used: natural rubber bearings (NRB) and lead rubber bearings (LLRB). Three different designs for the LLRB were tested; each design had a different diameter of lead plug, and thus, different damping values. Artificial time histories of peak ground acceleration 0.4g were used in both the tests and the analyses. In both shaking table tests and analyses, as expected, the acceleration responses of the seismically isolated test structure were considerably reduced. However, the shear displacement at the isolators was increased. To reduce the shear displacement in the isolators, the diameter of the lead plug in the LLRB had to be enlarged to increase isolator damping by more than 24%. This caused the isolator stiffness to increase, and resulted in amplifying the floor acceleration response spectra of the isolated test structure in the higher frequency ranges with a monotonic reduction of isolator shear displacement. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

应用CP网络进行岩性识别   总被引：2，自引：3，他引：2  

陆万雨  黄盛仁  覃世银 《吉林大学学报(地球科学版)》2002,32(1):100-102

为通过测井解决岩性识别问题，引入了具有分类准确、算法简练等优点的CP（Counter-Propagation)网络。在详细介绍CP网络的网络模型和算法的基础上，结合某油田的实际测井资料，进行了CP网络识别研究。应用结果表明：CP网络训练周期短、识别准确率高、不存在收敛问题。通过试验研究得出结论：CP网络完全可以用于解决岩性识别等问题，具有广阔的应用前景。  相似文献   

吉林省药用赋形剂膨润土资源的优选研究   总被引：2，自引：0，他引：2  

田莉玉  王玉洁  王丽荣  贺义兴  刘万 《吉林大学学报(地球科学版)》2002,32(3):307-311

对吉林省九台，小梨河，净月潭和露水河等产地的膨润土进行了质量优选研究。根据膨润土类型，蒙脱石含量，理化性能和浸出试验结果，发现净月潭灰白色钙基膨润土的品质最优，其次最小梨河浅黄色膨润土。  相似文献   

泌阳凹陷湖相碳酸盐岩未成熟石油的形成条件   总被引：8，自引：0，他引：8  

邵宏舜  黄杏珍  闫存凤  马万怡  贾敏 《地球化学》2002,31(3):266-272

泌阳凹陷下第三系核桃园组H3^1-H2^3段湖相白云岩，分布有未熟油的工业性油流，原油来自同层段的湖相泥质白云岩，属自生自储式原油，通过凹陷中心云2井和云1井岩芯的有机地球化学研究，论述了白云岩系未熟油形成的内因和外因，有机质丰度高和优良的成油母质类型（包括被细菌改造“腐泥化”的母质）和良好的岩性组合是早期成油的物质基础；双层水体的咸水碱性环境是早期成油的外界条件。其成烃模式表明，泌阳凹陷湖相碳酸盐岩存在早期和晚期两个成烃高峰期。  相似文献   

离散裂隙渗流方法与裂隙化渗透介质建模   总被引：4，自引：1，他引：4  

王明玉  陈劲松等 《地球科学》2002,27(1):90-96

流体渗流模拟的连续介质方法通常适用于多孔地质体，并不一定适用于裂隙岩体，由于裂隙分布及其特征与孔隙差异较大。若流体渗流主要受裂隙的控制，对于一定尺寸的裂隙岩体，多孔介质假设则较难刻划裂隙岩体的渗流特征。离散裂隙渗流方法不但可直接用于模拟裂隙岩体非均质性和各向异性等渗流特征，而且可用其确定所研究的裂隙岩体典型单元体及其水力传导（渗透）张量大小。主要讨论了以下问题：（1）饱和裂隙介质中一般的离散流体渗流模拟；（2）裂隙岩体中的REV（典型单元体）及其水力传导（渗透）张量的确定；（3）利用离散裂隙网络流体渗流模型研究裂隙方向几何参数对水力传导系数和REV的影响；（4）在二维和三维离散裂隙流体渗流模型中对区域大裂隙和局部小裂隙的处理方法。调查结果显示离散裂隙流体渗流数学模型可用来评价不同尺度上的裂隙岩体的水力特征，以及裂隙方向对裂隙化岩体的水力特征有着不可忽视的影响。同时，局部小裂隙、区域大裂隙应当区别对待，以便据其所起的作用及水力特征，建立裂隙化岩体相应的流体渗流模型。  相似文献   

秦岭若干重要类型金矿床成矿地质条件研究新进展   总被引：6，自引：0，他引：6  

韦龙明  吴列善  黄建军  李福东  朱华平  邹湘华  张万业  任小华 《矿产与地质》2002,16(2):65-69

通过秦岭金矿区域成矿地质条件研究取得的进展 :八卦庙矿区发育有条带状的热水沉积岩 ,金矿床类型属于热水沉积韧性剪切带改造型 ,矿化类型为细脉浸染型 ;马鞍桥金矿的成矿大地构造环境属于华北板块南缘 ,含矿岩系为早古生代的深水斜坡浊积岩相 ,矿区的“浅色岩相”系变质成因 ;煎茶岭金矿属构造蚀变岩型金矿 ,而非超基性岩浆热液型金矿。以上研究为秦岭地区金矿找矿指出了新方向和新类型  相似文献   

An Agricultural Land Resource Assessment Study Based on GIS—An Example from Guiyang City     

刘建军  李春来  万鹰昕 《中国地球化学学报》2002,21(1):79-88

This paper assesses the agricultural land resources of Guiyang City by means of GIS,on the basis of the pressure-state-response model in which soil heavy metal contamination is selected as a pressure indicatror.he results suggest that most of the agricultural land resources are of good quality,However,there are 17.11km^2 dry land and paddy field,which belong to the region of serious heavy metal contamination and are not fit for planting crops.At the same time,the high quality plowland,which is suitable for cultivation,has decreased nearly by 1/3 due to soil heavy metal contamination.These findings may improve our understanding that it is very important to prevent and cure heavy metal contamination of Guiyang City.  相似文献   

Hydrothermal Redistribution of Rare—Earth Elements in Pingxiang Dacite,Guangxi     

顾尚义  万国江  毛健全  张启厚 《中国地球化学学报》2002,21(2):170-174

Distribution of the rare-earth elements (REE) in dacite has been studied so as to get a better understanding of the migration behavior of REE during alteration. Both unaltered and altered samples were collected in an unpolluted area of Guangxi Zhuang Autonomous Region, southwest China. The REE concentrations were analyzed by ICP-MS. It is concluded that the REE were enriched during dacite alteration in varying degrees. The chondrite-normalized REE patterns of altered samples approximately maintain the characteristics of unaltered samples. However, if we normalize the REE concentrations of altered samples with unaltered dacite, fractionation of REE will appear. The LREE are more enriched than HREE in all altered samples with the LREE possibly precipitated as carbonate minerals. Both positive and negative Eu anomalies exist. Enrichment, immobility and depletion are noticed for the element Lu. Heavy mineral alteration, difference in stability constant between carbonate LREE and HREE complexes, downward migration of weathering fluid and microenvironment change may be responsible for the fractionation of REE in the altered dacite.  相似文献   

Use of Chemotaxonomy To Study the Influence of Benzalkonium Chloride on Bacterial Populations in Biodegradation Testing     

Klaus Kümmerer  Ali Al‐Ahmad  Almut Henninger 《洁净——土壤、空气、水》2002,30(4):171-178

Contradictory results are reported for the behaviour of quaternary ammonium compounds (QACs) in sewage treatment plants (STPs). QACs may sorb onto activated sludge. Only little information is available with respect to effects of QACs against bacteria in STPs. Only 5 to 15 % of bacteria present in sewage sludge can be detected by means of culture dependent microbiological methods. The shift of the bacterial populations due to effects of test compounds have not been studied up to now with culture independent methods. The microbial populations shift was studied in situ using culture independent chemotaxonomy profiling ubiquinones and polyamines. Additionally, toxic effects of QACs against bacteria present in the test vessels of the Zahn‐Wellens test (OECD 302 B) were assessed with a toxicity control in the test. The ubiquinone profiles representing changes in Gram‐negative populations mainly showed that the activated sludge was affected only in test vessels containing benzalkonium chloride. According to chemotaxonomy Acinetobacter or/and some members of Pseudomonas spp. have been selected by benzalkonium chloride after some adaptation period (8 to 12 days).  相似文献