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1.
MR智能基础隔震结构的抗震分析   总被引:1,自引:0,他引:1  
麦庆元  韦树英 《广西科学》2005,12(4):292-294,299
为研究MR智能基础隔震结构的抗震性能,应用双线性恢复力模型来描述基础橡胶隔震垫的弹塑性特性,通过模糊半主动控制策略计算MR阻尼器的控制力,建立该混合控制结构的数学模型,并对某MR智能基础隔震的框架结构进行地震作用下的时程反应分析.仿真分析表明:MR智能基础隔震系统不仅能够减小上部结构的地震反应,而且还能够有效地保护基础隔震系统免于因过大变形而产生失效破坏,说明MR智能基础隔震结构是一种性能优异的智能控制系统.  相似文献   

2.
新型磁流变阻尼器及其在结构振动半主动控制中的应用   总被引:8,自引:0,他引:8  
应用磁流变阻尼器对结构振动进行控制,对磁流变阻尼器的力学模型进行了介绍,并设计了磁流变阻尼器的结构参数;基于现代最优控制理论的半主动控制方法设计了控制器,数值计算结果表明:采用磁流变阻尼器对结构振动进行半主动控制,在输入El-Centro波,Taft波及人工地震波时,可使受控结构的各层位移响应的控制效果超过50%,能够有效地减小结构的地震反应。  相似文献   

3.
基于国际通用Benchmark隔震模型,提出了一种基于磁流变阻尼器的负刚度智能隔震控制策略及其一组有效控制参数.采用Matlab模拟分析了双向地震作用下普通隔震、H2/LQG主动控制、H2/LQG-clipped半主动控制、Passive-on被动控制和拟负刚度控制时模型的地震反应,对比分析了250条不同场地地震波下五种控制方式的控制效果和适应性.结果表明:拟负刚度智能隔震集合了主动和传统半主动控制的优点,其综合控制性能最优,能同时有效降低大地震时隔震层位移和中小地震时上部结构地震反应.研究了不同断层距的近场地震下不同控制方式隔震结构地震反应,得出了近场影响系数.  相似文献   

4.
电磁流变智能半主动控制系统的发展与应用   总被引:1,自引:0,他引:1  
针对电磁流变智能产坟动控制系统具有性能稳定、反应迅速、能耗小、控制效果良好等特点,及其在结构控制方面的应用前景,介绍电磁流变智能半主动控制系统及其有关的电磁流变液、控制器及控制算法、驱动器、传感器、电磁流变阻尼器等部分的功能、应用和发展状况,指出其在结构振动控制中进一步应用所亟待解决的问题。  相似文献   

5.
为了研究MR智能基础隔震结构的抗震性能,建立了该混合控制结构的力学模型,橡胶垫隔震层采用双线型恢复模型描述其弹塑性特性。运用自适应神经网络模糊系统(ANFS)计算MR阻尼器的控制力,在SIMULINK环境下对控制结构进行仿真动力分析,并对具体结构进行地震作用下的时程反应分析,仿真分析表明:自适应神经网络模糊系统可以有效地应用到结构控制中,并证实了MR基础隔震结构是一种性能优异的智能控制系统。  相似文献   

6.
针对铅芯橡胶垫作为一种被动控制装置,存在最优控制范围窄的局限性,将磁流变阻尼器与橡胶隔震垫相结合,组成智能基础隔震系统应用于结构振动控制中,数值模拟分析了结构在不同地震波、不同地震力作用下铅芯橡胶隔震垫隔震和MR智能隔震下的反应.计算结果表明:MR智能基础隔震可以对宽频域不同大小的地震激励提供最优控制.  相似文献   

7.
MRD与LRB相混合的结构振动控制   总被引:4,自引:0,他引:4  
磁流变阻尼器(MRD)利用磁流变液提供可控性是当今最有前途的半主动控制装置,附加MRD是铅芯橡胶垫(LRB)隔震结构的发展方向.因此提出3种MRD与LRB隔震混合方案,建立了MRD与LRB隔震混合结构的动力分析模型,推导出运动微分方程,对其进行时程反应分析.以7层框架结构为例,采用瞬时最优控制算法分别对3种混合方案进行地震反应分析,与LRB隔震结构进行比较,各混合方案的各种地震反应均明显得到更好地控制,而混合方案3的控制效果最显著.  相似文献   

8.
文章根据高架桥的结构特点,将整个结构简化为多自由度(MDOF)体系,采用磁流变(MR)阻尼器中修正的Bouc-Wen模型和剪切型最优控制(clipped-optimal control)算法对高架桥的地震响应进行了半主动控制研究;同时将MR阻尼器半主动控制与结构被动控制和主动控制的效果进行了对比研究;使用EI-Centro波、Taft波和天津波3种地震波对高架桥-MR阻尼器半主动控制系统进行了数值模拟计算。数值结果表明:基于MR阻尼器的半主动控制能够有效地减小高架桥的水平地震位移,其控制效果明显优于被动控制,且接近于主动控制。  相似文献   

9.
对渤海JZ20-2MUQ导管架式海洋平台1:10比例模型结构进行数值分析.首先,对模型结构进行了参数影响分析,确定了隔震橡胶垫的基本参数;然后,根据阻尼器性能试验结果,确定了磁流变阻尼器的基本设计参数;最后,采用多种地震作用对模型结构进行了时程分析.结果表明:磁流变阻尼隔震控制方案有效地减少了导管架结构的振动、甲板层的加速度和隔震层的层间变形.为模型结构的试验研究提供了合理的设计参数,并验证了方案的可行性.  相似文献   

10.
介绍了磁流变阻尼器的性能及恢复力模型,提出了两种简易可行的半主动控制策略.三层框架结构的地震反应分析表明,策略2优于策略1和被动控制,该控制方法能够有效减小结构的地震反应.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

15.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

16.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

17.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

18.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

19.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

20.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

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