Multi‐objective optimal design of FLC driven hybrid mass damper for seismically excited structures     

A. S. Ahlawat  A. Ramaswamy 《地震工程与结构动力学》2002,31(7):1459-1479

Structural vibration control using active or passive control strategy is a viable technology for enhancing structural functionality and safety against natural hazards such as strong earthquakes and high wind gusts. Both the active and passive control systems have their limitations. The passive control system has limited capability to control the structural response whereas the active control system depends on external power. The power requirement for active control of civil engineering structures is usually quite high. Thus, a hybrid control system is a viable solution to alleviate some of the limitations. In this paper a multi‐objective optimal design of a hybrid control system for seismically excited building structures has been proposed. A tuned mass damper (TMD) and an active mass driver (AMD) have been used as the passive and active control components of the hybrid control system, respectively. A fuzzy logic controller (FLC) has been used to drive the AMD as the FLC has inherent robustness and ability to handle the non‐linearities and uncertainties. The genetic algorithm has been used for the optimization of the control system. Peak acceleration and displacement responses non‐dimensionalized with respect to the uncontrolled peak acceleration and displacement responses, respectively, have been used as the two objectives of the multi‐objective optimization problem. The proposed design approach for an optimum hybrid mass damper (HMD) system, driven by FLC has been demonstrated with the help of a numerical example. It is shown that the optimum values of the design parameters of the hybrid control system can be determined without specifying the modes to be controlled. The proposed FLC driven HMD has been found to be very effective for vibration control of seismically excited buildings in comparison with the available results for the same example structure but with a different optimal absorber. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

柴达木北缘中生代盆地的成因类型及构造沉积演化   总被引：12，自引：0，他引：12  

和钟铧  刘招君  郭巍  董清水 《吉林大学学报(地球科学版)》2002,32(4):333-339

柴达木盆地是我国西部一个大型中新生代陆相含油气盆地。其剖面结构、构造样式、沉积特征、基底沉降、古地温等表明中生代盆地的性质应为挤压环境下经过多次幕式逆冲形成的、也祁连造山带有关的叠置前陆盆地，经历了早株罗世的破裂前陆盆地和中株罗世之后的类前陆盆地的演化过程。柴达缘中生代沉积充填由构造层序I（早株罗世）、构造层序Ⅱ（中侏罗世）和构造层序Ⅲ（晚侏罗世）三个完整的构造层序构成，由粗到细多个沉积旋回代表了逆冲加载过程中由活动期到平静期的转化过程。随着逆冲活动的加强和频率加快，构造层序Ⅳ（白垩纪）只经历逆冲活动期，是不完整的构造层序，发育补偿和过补偿沉积，盆地逐渐萎缩。  相似文献   

遗传算法在边坡数值计算中的应用   总被引：4，自引：0，他引：4  

安关峰  殷坤龙等 《地球科学》2002,27(2):177-180

改进了进化方向的遗传算法与有限元数值法，结合并研制了相应的软件。应用该软件对多类型岩土边坡进行弹性模量、内聚力、内摩擦角等参数反演分析，显示误差很小，收敛速度也很快，这说明改进进化方向遗传算法这种新型的优化算法在多类型岩土参数优化估计中具有独特的优势。  相似文献   

河南南召水洞岭铜铅锌矿床地质特征及成因分析   总被引：8，自引：0，他引：8  

伏雄 《矿产与地质》2002,16(3):160-164

通过地质详查和综合研究相结合的手段 ,从水洞岭铜铅锌矿床的地质特征入手 ,分析矿床成因 ,提出矿床属海相火山喷发沉积 -弱改造型的成因观点  相似文献   

燕山东段地区与花岗岩有关的几个问题探讨     

饶玉学 《矿产与地质》2002,16(6):327-331

详细研究了燕山东段地区花岗岩类的侵入时代、产出形式和成因类型 ,指出该区与花岗岩有关的三个金属成矿系列。  相似文献   

中国煤系高岭岩(土)资源成矿机理与开发利用   总被引：9，自引：0，他引：9  

刘钦甫  杨晓杰  张鹏飞  卞建玲 《矿物学报》2002,22(4):359-364

中国含煤地层中高岭岩（土）分布广泛，成矿时代多，成因复杂，储量丰富，质地优良，是一种重要的自然资源和非金属矿产，具有极高的开发利用价值，在全世界独具特色。本文研究了中国煤系高岭岩（土）资源概况、研究简史；根据成分、结构、地质产状等特征，提出了中国煤系高岭岩（土）的成因类型；对生物和有机质在其形成中的作用进行了分析和探讨，并结合有机酸溶解矿物模拟实验对其成矿作用做了初步探索；最后对煤系高岭岩的某些关键性加工技术进行了简述。  相似文献   

自然铜、铜合金矿物及其矿床形成机理新探索   总被引：8，自引：1，他引：8  

郑大中  郑若锋 《四川地质学报》2002,22(2):72-81

描述了自然铜、铜合金矿物及其矿床形成的新机制。在岩浆及热液中，铜及铜合金可呈氢化物、羧基配合物及纳米粒子活性、迁移、富集形成自然铜矿床，或经以后的地质事件，长期、多次迁移富集，叠加形成富而大的自然铜矿床。在表生条件下，铜的硫化矿物被氧化分解，可形成亚铜的硫代硫酸盐及氯配合物，部分可形成铜的硫酸盐配合物迁移，由于硫代硫酸盐被氧化，亚铜岐化可形成高纯度的自然铜，但它易氧化形成孔雀石、蓝铜矿、赤铜矿、黑铜矿、硅孔雀石等，因此很难形成自然铜矿床。  相似文献   

中条山同善天窗铜矿类型及找矿新认识     

王昊  郭红党  薛克勤 《华北地质》2002,(Z1)

在总结同善构造—剥蚀窗内成矿地质条件的前提下 ,运用成矿系列理论 ,把区内具有多种表现形式的变基性火山岩型、变砂岩型、大理岩型三大类铜矿分成了八种亚类 ,认为诸类铜矿与区内广泛发育的新太古代基性岩存在着成生联系 ,铜矿的形成经历了一个复杂的过程。早期的海底火山喷发带来的铁、铜、硫等成矿物质 ,经过最初的海水富集、火山活动末期的热液作用富集以及后来区域变质叠加富集进而形成了这一系列矿床。同时提出了新的找矿思路、找矿方法及找矿靶区。  相似文献   

Application of genetic BP network to discriminating earthquakes and explosions     

边银菊 《地震学报(英文版)》2002,15(5):540-549

Introduction Artificial Neural Network (ANN) is an important branch of artificial intelligence. It is proposed on the foundation of the study on modern neural science, is a man-made network that can implement some functions based on the mans comprehensive understanding for cerebral neural network (HAN, WANG, 1997). ANN is a mathematical model of simplified human brain neural network and is used to simulate the structures and functions of human brain neural network. ANN is a complex netw…  相似文献   

Genesis of chlorine and sulphur in fumarolic emissions at Vulcano Island (Italy): assessment of pH and redox conditions in the hydrothermal system     

V. Di Liberto  P. M. Nuccio  A. Paonita   《Journal of Volcanology and Geothermal Research》2002,116(1-2)

Chlorine- and sulphur-bearing compounds in fumarole discharges of the La Fossa crater at Vulcano Island (Italy) can be modelled by a mixing process between magmatic gases and vapour from a boiling hydrothermal system. This allows estimating the compounds in both endmembers. Magma degassing cannot explain the time variation of sulphur and HCl concentrations in the deep endmember, which are more probably linked to reactions of solid phases at depth, before mixing with the hydrothermal vapours. Based on the P–T conditions and speciation of the boiling hydrothermal system below La Fossa, the HCl and S_tot contents in the hydrothermal vapours were used to compute the redox conditions and pH of the aqueous solution. The results suggest that the haematite–magnetite buffer controls the hydrothermal fO₂ values, while the pH has increased since the end of the 1970s. The main processes affecting pH values may be linked to Na–Ca exchanges between evolved seawater, feeding the boiling hydrothermal system, and local rocks. While Na is removed from water, calcium enters the solution, undergoes hydrolysis and produces HCl, lowering the pH of the water. The increasing water–rock ratio within the hydrothermal system lowers the Ca availability, so the aqueous solution becomes less acidic. Seawater flowing towards the boiling hydrothermal brine dissolves a large quantity of pyrite along its path. In the boiling hydrothermal system, dissolved sulphur precipitates as pyrite and anhydrite, and becomes partitioned in vapour phase as H₂S and SO₂. These results are in agreement with the paragenesis of hydrothermal alteration minerals recovered in drilled wells at Vulcano and are also in agreement with the isotopic composition of sulphur emitted by the crater fumaroles.  相似文献