Robust H∞ control for aseismic structures with uncertainties in model parameters     

宋刚  林家浩  赵岩 《地震工程与工程振动(英文版)》2007,6(4):409-416

This paper presents a robust H∞ output feedback control approach for structural systems with uncertainties in model parameters by using available acceleration measurements and proposes conditions for the existence of such a robust output feedback controller. The uncertainties of structural stiffness, damping and mass parameters are assumed to be norm-bounded. The proposed control approach is formulated within the framework of linear matrix inequalities, for which existing convex optimization techniques, such as the LMI toolbox in MATLAB, can be used effectively and conveniently. To illustrate the effectiveness of the proposed robust H∞ strategy, a six-story building was subjected both to the 1940 El Centro earthquake record and to a suddenly applied Kanai-Tajimi filtered white noise random excitation. The results show that the proposed robust H∞ controller provides satisfactory results with or without variation of the structural stiffness, damping and mass parameters.  相似文献   

开挖边坡随机楔体稳定分析与加锚优化方法   总被引：1，自引：1，他引：1  

张发明  贾志欣  陈祖煜 《水文地质工程地质》2002,29(5):15-18

随机楔体的破坏是岩石开挖边坡中常见的破坏类型之一，在对组成楔体的结构而调查统计的基础上，应用随机模拟的方法，生成开挖边坡的三维裂隙网络，进一步运用随机搜索方法与块体理论，搜索出边坡面上的随机楔体，进行楔体的稳定分析，采用风险设计的理论，建立系统锚杆的优化设计方法，将研究结果应用于小湾水电站进水口开挖边坡的稳定分析与锚固优化设计中，得到了较为可信的结果。  相似文献   

A Report on a Biotite-Calcic Hornblende Geothermometer   总被引：1，自引：0，他引：1  

WU Chunming  PAN Yusheng  WANG Kaiyi  ZHANG Jian Institute of Geology  Chinese Academy of Geological Sciences  Beijing Institute of Geology  Geophysics  Chinese Academy of Sciences  Beijing Department of Earth Sciences  The Graduate School  Chinese Academy of Sciences  Beijing 《《地质学报》英文版》2002,76(1):126-131

This paper presents a biotite-calcic hornblende geothermometer which was empirically calibrated based on the gamet-biotite geothermometer and the gamet-plagioclase-hornblende-quartz geobarometer, in the ranges of 560-800℃ (T) and 0.26-1.4 GPa (P) using the data of metadolerite, amphibolite, metagabbro, and metapelite collected from the literature. Biotite was treated as symmetric Fe-Mg-AlVI-Ti quaternary solid solution, and calcic hornblende was simplified as symmetric Fe-Mg binary solid solution. The resulting thermometer may rebuild the input garnet-biotite temperatures well within an uncertainty of ±50℃. Errors of ±0.2 GPa for input pressure, along with analytical errors of ?% for the relevant mineral compositions, may lead to a random error of ±16℃ for this thermometer, so that the thermometer is almost independent of pressure estimates. The thermometer may clearly discriminate different rocks of lower amphibolite, upper amphibolite and granulite facies on a high confidence level. It is assume  相似文献   

3D裂隙网络随机模拟及其工程应用研究   总被引：2，自引：2，他引：2  

张发明  汪小刚  贾志欣  弥宏亮  陈祖煜 《现代地质》2002,16(1):100-103

岩体中存在的大量随机分布的裂隙对岩体的工程性质及稳定性有着极其重要的影响。传统的工程地质研究方法难以客观地描述其空间分布特征。应用概率与统计学的理论 ,通过统计分析得到裂隙的分布规律性 ,采用随机模拟的方法实现与统计分布相适应的裂隙网络是研究随机裂隙宏观特征的有效途径。通过模拟所得的 3D裂隙网络 ,进一步研究了裂隙的连通特征及工程开挖面上的稳定分析与加固措施优化的方法  相似文献   

The formation of caustics in two‐ and three‐dimensional media     

Jesper Spetzler  Roel Snieder 《Geophysical Journal International》2001,144(1):175-182

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边坡稳定可靠性的随机有限元分析   总被引：9，自引：2，他引：9  

傅旭东  茜平一  刘祖德 《岩土力学》2001,22(4):413-418

随机有限元法可以处理土性参数的变异性和空间相关性。对二阶摄动随机有限元法的摄动理论和程序进行了研究，提出了偏导矩阵的组集方法，采用正态分布随机变量的正交变换法来提高计算效率。考虑土性参数随机场作用和土性指标之间的互相关性，建立边坡局部抗剪和总体稳定性可靠度的随机有限元分析模型，对某实际土坡进行了可靠度计算，计算结果较为符合实际。  相似文献   

Non‐stationary seismic response of tanks with soil interaction by wavelets     

Pranesh Chatterjee  Biswajit Basu 《地震工程与结构动力学》2001,30(10):1419-1437

A wavelet‐based random vibration theory has been developed for the non‐stationary seismic response of liquid storage tanks including soil interaction. The ground motion process has been characterized via estimates of statistical functionals of wavelet coefficients obtained from a single time history of ground accelerations. The tank–liquid–soil system has been modelled as a two‐degree‐of‐freedom (2‐DOF) system. The wavelet domain equations have been formulated and the wavelet coefficients of the required response state are obtained by solving two linear simultaneous algebraic equations. The explicit expression for the instantaneous power spectral density function (PSDF) in terms of the functionals of the input wavelet coefficients has been obtained. The moments of this PSDF are used to estimate the expected pseudo‐spectral acceleration (PSA) response of the tank. Parametric variations are carried out to study the effects of tank height, foundation natural frequency, shear wave velocity of soil and ratio of the mass of tank (including liquid) to the mass of foundation on the PSA responses of tanks. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   

Seismic interaction in linearly connected electrical substation equipment     

A. Der Kiureghian  J. L. Sackman  K‐J. Hong 《地震工程与结构动力学》2001,30(3):327-347

An electrical substation consists of a complex set of equipment items that are interconnected through conductor buses or cables. If the connections are not sufficiently flexible, significant dynamic interaction may occur between the connected equipment items during a seismic excitation. This interaction is believed to be responsible for some of the observed substation equipment damage in recent earthquakes. This paper investigates the interaction between two equipment items connected by a linear spring‐dashpot or spring‐dashpot‐mass element representing a conductor bus. It is found that the interaction between the two equipment items may significantly amplify the response of the higher‐frequency equipment item. The influences of various key parameters on the interaction effect are quantified. Means for reducing the adverse interaction effect are described. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   

Frequency Analysis of Heavy Tamping Vibration     

Sun Jinzhong College of Engineering  Technology  China University of Geosciences  Beijing Tan Hanhua Guizhou Institute of Communication Design  Guiyang Qi Shengwen Institute of Geology  Chinese Academy of Sciences  Beijing 《中国地质大学学报(英文版)》2001,12(2)

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一种基于马尔可夫随机场的影像纹理分类方法     

黄桂兰  郑肇葆 《武汉大学学报(信息科学版)》1996,(3)

针对纹理影像先估计出其马尔可夫随机场参数，后运用多元统计分析中模糊聚类分析的数学方法进行定量分类，从而为解决划分上的不确定性现象找出描述方法，获得客观的分类结果  相似文献