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1.
AUTHOR INDEX     
《中国颗粒学报》2006,4(6):360-361
Abdullah, E.C. 104 Adams, M. 35 Aldinger, F. 9 Antiohos, S.K. 73 Bai, B. 220 Bai, H. 77 Bao, L. 300 Beltramini, J.N. 80 Bi, H.-T 103,127,194 Boyko, M.N. 70 Brandl, H. 93 Cao, G. 20 Cao, J. 316,346 Chaniotakis, E. 234 Chatenet, B. 330 Che, H. 20,327 Chen, H. 330 Chen, H. 153 Chen, J. 300 Chen, J. 238 Chen, Q. 238 Chen, X. 25 Cheng, Y. 108,312 Chen, Y. 323 Chen, Z. 327 Chouliara, E. 73 Chow, J. 259,346 Cui, H. 183 Dai, M. 293 Ding, Z. 60 Dong, J. 346 Du, B. 1 Du, H. 25…  相似文献   

2.
AN IMPROVEMENT AND PROOF OF OGY METHOD   总被引:8,自引:0,他引:8  
I.IntroductionRecenhycontrollingchaosbecomesaninterestingsubject.In1990,E.Ott,C.GreogiandJ.A.Yorkelllgaveacollceptionofcontrollingchaos,andgaveacontrollingmethodknownasOGYmethod.ThereweremanyresultsthatshowedOGYmethodiseffective.AfterOGY,manymethodsofcontrollingchaosweregiven,mostofthemwerebasedonOGY13'4'5'6'71.SoOGYmethodisthefundamentofcontrollingchaos.ToachieveaproofofOGYisanimportanttaskformathematicstheoryofcontrollingchaos.Thispaperchangesthemethodofchoosingparameter,andprove…  相似文献   

3.
I.IntroductionUsedextensivelyillengineeringareone-wayrectallgularsteppedthinplates.suchaslongandnarrow"platesofl'Oundationbaseincivilengineering,high-c"a}'surface.retainingwall,undergroundstructurefi-ame,baseplatesofsluice.shipyardando\-ertlowdam.Theyshouldnotonlymeetrequirementsofstrength,stiffnessalldsteadinessofstructuresbutalsosavematerialstotileftlll.Thus,steppedstructuresarecolnmonl}'adoptedinengineerings.Sofar.vibratio,nsofsuChplateshavenotbeendiscussedinanyliterature.Inthispaper.disc…  相似文献   

4.
Anti-plane shear waves scattering from a partially debonded magneto-electro- elastic circular cylindrical inhomogeneity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Du Jianke, Shen Yapeng, Tian Weiping I-1Wave superposi…  相似文献   

5.
I.IntroductionBecauseofthenonlinearityoflargedeflectionproblemofthinplates,itisquitedifficulttoobtainitsaccuratesolution.Thereforeanapproximatesolutiontoitobtainedbyanappropriatemethodisdesired.Thetechniquesocalledperturbation,beingabletogiveresultswithadequateprecision,isofaprevailingandeffectiveonetobegenerallyaccepted.W.Z.Chientl]succesfullyobtainedanapproximatesolutiontothelargedeflectionproblemofthincircularplatefie-curalaxisymmetricallybyperturbationtechnique.X.Z.Wangl'Jgainedthedispl…  相似文献   

6.
I.IntroductionInreallife,inengineering,innature,andinthesociety,thereexisteverykindoftimeseriesproblems.Becausenonlinearfactorsareextensivelyimplicatedilltiledynamicsystemsofvariousfields,thebehaviourofthesystemscantakethecomplicatedanddiverseforms.Atpresent,twodifferentmethodsareusedtostudytheproblemoftinleseries.Ollemethodistoadoptthetheoryofrandomprocessonthebasisofprobabilitytheory.Andthistheoryisusedtofoundthesystemlinearmodel.Thismethodhasalreadybeenstudiedperfectly.Forexample,determin…  相似文献   

7.
1.IntroductionThecompositereinforcedbysphericalparticlesisanilllportantengilleel-lugmaterial.Itiswidelyusedinvariousfieldsuchasaviationandspaceflight.Withl'egardtoitsefttctivemodulusproblenl,maily1llodelsandmethodswereproposedillpilotyeal's.Somethed.eticalpredictionlbrnlulaehavebeenobtailledtitpresent,whicharequiteinagreementwithexpel.imelltalresultslll.FIowcver,becausedemandingl'orcompositeincllglneeri11gtlpplicationbecomeslargel'daybyday,theSurftlcecoatillgofreinforcednlatel.iLtlincomposit…  相似文献   

8.
9.
I.IntroductionFI.actillilltcrpolationwastlrstpEltforwardbyunA]ncrica1llathematician,M.F.Barllsley.in1986.ItgivesanewInethodologytardataf'ittillg,whichnotonlyopedsupanewresearch11eldfol'tilnctiollappl'oachingtheory,butalsoprovidespowerfultoolsforcolnptltcrgraphicsThistool'sapplicabilityisnowfilllyappreciated.Theuseoflinearfunctions,polynomialfunctionsandSurtllcespringfunctionstoestablishvariousmeterialobjectmodelsinreallifefi-omtraditionalEuclideangeometryisnowcommonpractice.Theavailabilit…  相似文献   

10.
11.
An online method of identification of dynamic characteristics only using measured ambient response of structural dynamic system is widely focused on. The Ibrahim and ARMA ( AutoRegressive Moving Average ) methods are basic identification methods. A model on dynamic system suffered by random ambient excitation was researched into, and a subspace decomposition methodwas introduced. Robustness and effectiveness of this approach on identification of vibration characteristics are demonstrated on numerical experiment.  相似文献   

12.
In this paper, the on-orbit identification of modal parameters for a spacecraft is investigated. Firstly, the cou-pled dynamic equation of the system is established with the Lagrange method and the stochastic state-space model of the system is obtained. Then, the covariance-driven stochas-tic subspace identification (SSI-COV) algorithm is adopted to identify the modal parameters of the system. In this algo-rithm, it just needs the covariance of output data of the system under ambient excitation to construct a Toeplitz matrix, thus the system matrices are obtained by the singular value decom-position on the Toeplitz matrix and the modal parameters of the system can be found from the system matrices. Finally, numerical simulations are carried out to demonstrate the validity of the SSI-COV algorithm. Simulation results indi-cate that the SSI-COV algorithm is effective in identifying the modal parameters of the spacecraft only using the output data of the system under ambient excitation.  相似文献   

13.
All structures exhibit some form of damping, but despite a large literature on the damping, it still remains one of the least well-understood aspects of general vibration analysis. The synthesis of damping in structural systems and machines is extremely important if a model is to be used in predicting vibration levels, transient responses, transmissibility, decay times or other characteristics in design and analysis that are dominated by energy dissipation. In this paper, new structural damping identification method using normal frequency response functions (NFRFs) which are obtained experimentally is proposed and tested with the objective that the damped finite element model is able to predict the measured FRFs accurately. The proposed structural damping identification is a direct method. In the proposed method, normal FRFs are estimated from the complex FRFs, which are obtained experimentally of the structure. The estimated normal FRFs are subsequently used for identification of general structural damping. The effectiveness of the proposed structural damping identification method is demonstrated by two numerical simulated examples and one real experimental data. Firstly, a study is performed using a lumped mass system. The lumped mass system study is followed by case involving numerical simulation of fixed–fixed beam. The effect of coordinate incompleteness and robustness of method under presence of noise is investigated. The performance of the proposed structural damping identification method is investigated for cases of light, medium, heavily and non-proportional damped structures. The numerical studies are followed by a case involving actual measured data for the case of a cantilever beam structure. The results have shown that the proposed damping identification method can be used to derive an accurate general structural damping model of the system. This is illustrated by matching the damped identified FRFs with the experimentally obtained FRFs.  相似文献   

14.
反求压电薄板智能结构荷载的有限元逆逼近方法   总被引:4,自引:0,他引:4  
基于压电薄板智能结构提出一种有限元逆逼近反求结构荷载参量的方法,逼近目标函数以压电电荷响应为参量,迭代初值采用单位荷载预逼近方法;数值算例表明了该方法的有效性,可用于解决压电智能结构的荷载识别问题。  相似文献   

15.
陈光  王永 《实验力学》2008,23(2):141-148
密集模态挠性结构的模态不仅阻尼小而且耦合程度高,给模型辨识带来了很大困难.频域辨识是获取空间挠性结构模型的一个有效方法,但是目前频域辨识要么模型结构定义有缺陷,要么是集中在单变量情形,不适合作大型空间挠性结构多变量模型的辨识.本文提出了多变量极大似然频域辨识,给出了其模型结构定义、算法推导及实现,并将其应用于H型密集模态挠性板的模型辨识,根据辨识结果,设计主动控制律,实现了对密集模态挠性板振动的有效抑制,表明了辨识算法及主动控制的可行性.  相似文献   

16.
本文针对现有的损伤识别方法不能满足部分结构损伤识别精度要求的现状,对结构的小损伤精确识别方法开展研究.以长细结构为研究对象,对具有不同损伤位置和损伤程度的圆柱形的轻阻尼梁结构进行了数值分析和实验研究,应用数值计算方法和实验确定的特征向量和特征频率对长细结构裂缝参数进行识别计算.本文在研究过程中编制了一个创新性的预测程序,通过其一次性生成目标函数图来选择合适的初始参数,从而对识别结果进行分析.研究结果表明,应用本文提出的识别方法,裂缝位置的识别误差可以控制在0.05 %~0.28 %范围内,裂缝深度识别误差低于7 %.  相似文献   

17.
结构运行状态下的模态参数提取是结构健康监测系统需要解决的关键问题之一.自然激励技术的提出为大型复杂工程结构运行状态下的模态参数提取提供了一条新的途径.原始自然激励技术给出了单输入白噪声激励下利用结构位移响应的互相关函数进行模态识别的理论模型,对于多输入情况则缺乏相应的理论模型.本文在单输入理论模型的基础上进一步发展了自然激励技术:推导了多输入独立白噪声激励下多自由度系统结构位移响应的互相关函数的解析公式,并分析了它与单输入情况下互相关函数之间的关系;基于此互相关函数定义了一个新函数,证明它含有结构各阶模态信息,可以表达为一系列衰减正弦函数之和,并且各个组分正弦函数的频率等于各阶模态的有阻尼固有圆频率;提出了以新函数为核心的同时适用于单输入和多输入情况的模态识别算法,建立了自然激励技术的统一模型.  相似文献   

18.
This paper presents a static method for the axial load identification of slender prismatic beams with uncertain length and unknown boundary conditions as is typical of struts and ties of truss structures or tie-rods of arches and vaults. The proposed method requires the knowledge of the beam flexural rigidity only. Flexural displacements or curvatures are measured at five cross sections of the beam subjected to an additional concentred lateral load. Unlike analogous dynamic methods, any set of experimental data may be used in the identification algorithm. The proposed algorithm is verified by means of many numerical and experimental tests on beams having different boundary conditions. Excellent estimates of the axial forces are obtained when the greatest possible distance between sensors is adopted, even if in the presence of high values of the axial forces very accurate displacement measurements are required.  相似文献   

19.
The analysis of parameterised nonlinear models is considered. In particular the emphasis is placed on models produced as a result of applying nonlinear system identification techniques. A qualitative approach is taken, calling upon ideas from bifurcation theory. When combined with an existing numerical method this approach enables the analysis of a variety of nonlinear model forms to be carried out. The combination of qualitative and numerical aspects provides a flexible framework for analysis and in addition adds a global perspective that is difficult to achieve using analytical methods alone. When combined with the well tried methods of system identification, the approach allows the validation of nonlinear models from a qualitative viewpoint to be carried out. The method contrasts well with the statistical model validation techniques traditionally used. The technique is applied to a number of examples.  相似文献   

20.
结构处于自然环境中常会受到环境温度变化的影响,引起实测动力响应出现较大误差,进一步影响对结构健康状况的判定。另外,基于优化算法的损伤识别在反演损伤位置及量化损伤程度时,易出现局部最优解,且计算效率低下。针对以上难题,本文提出一种结合支持向量机与强化飞蛾扑火优化算法的损伤识别方法,用于对环境温度影响下的结构稀疏损伤进行识别。该方法首先采取支持向量机对环境温度变化进行量化分析;随后引入稀疏正则化确定稀疏损伤工况;接着将获得的环境温度变化及损伤工况信息作为强化飞蛾扑火优化算法的初始种群生成依据,从而得到针对实际损伤的初始种群用于缩小算法搜索空间,提高计算效率。最后采用基于频率的结构多损伤定位保证准则及模态应变能基本因子构建目标函数,通过考虑环境温度及随机噪声双重影响的简支梁数值算例以及I-40钢-混组合体系桥梁工程实例验证了本文所提方法的可行性。  相似文献   

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