带调谐液体阻尼器结构的有限元模拟分析

调频液体阻尼器(TLD)作为一种被动耗能减震装置,由于涉及到两种形态的物质之间的相互作用,真实准确地掌握调谐液体阻尼器的减震特性显得尤为困难,因此建立更加精确的流固耦合模型,进而探讨带调谐液体阻尼器结构的抗震性能是一件非常有意义的工作.本文利用ADINA有限元分析软件分别建立了结构动力学模型和流体动力学模型,并利用其流一固耦合分析模块,对此耦合模型进行瞬态分析,模拟计算结果与试验简化模型的结果具有较好的一致性.在此基础上通过动力时程分析得到了调谐液体阻尼器流场的变化特性,并结合流场特性考查了频率比、地震动、质量比这三个因素对带调频液体阻尼器结构抗震性能的影响,对比分析表明频率比对TLD的减振性能的影响最为显著,最后给出了TLD的设计建议.     

调谐液体阻尼器对高层建筑和高耸结构动力反应控制研究综述

本文就调谐液体阻尼器（TLD）对高层建筑和高耸结构动力反应控制的研究进展作了综述。重点介绍了TLD减振控制的理论与试验研究主要成果、部分工程应用实例与控制效果，并指出了今后值得进一步研究的某些问题。     

基于等效力控制方法TLD减振结构振动台子结构试验

通常采用数值模拟和小比例尺试验的方法研究调谐液体阻尼器(TLD)对结构的减振控制效果。由于TLD依靠水的晃动来提供减振力,精确的数值模型不易建立;另外,振动台模型试验又只能进行小比例尺试验,难以真实反映原型结构性能。为了解决这个问题,提出基于等效力控制方法的振动台子结构试验方法,以真实揭示TLD减振控制结构的抗震性能。通过试验研究得到如下结论:(1)惯性试件的振动台子结构试验结果与精确解吻合很好,表明基于等效力控制方法振动台子结构试验具有很好的精度;(2)TLD减振控制三层钢框架系统的振动台全结构和子结构试验结果吻合较好,进一步证明了基于等效力控制方法振动台子结构试验具有很好的精度。     

TLD抑制拉索振动的试验研究

针对现有减振方法对拉索振动控制的不足,尝试利用调谐液体阻尼器(TLD)抑制拉索振动。首先设计了TLD模型,并进行了TLD单体试验,其次对Cable-TLD组合系统进行了试验研究。研究表明利用TLD抑制拉索振动是可行的。其研究为同时控制拉索面内外复杂耦合振动提供了一种新思路。     

新型减振装置TL-PD的风洞模型试验研究

高柔结构动力反应强烈,对结构安全性和舒适性带来了挑战。为经济有效地控制高柔结构的动力响应,各种减振措施相继被提出,并在研究和实践中不断取得进展。文章发展了一种将调谐液体阻尼器(TLD)与颗粒阻尼器(PD)结合的新型减振耗能装置TL-PD,尝试用于高柔结构的振动控制。为验证该装置的风振控制效果,将简易TL-PD装置安装于一高层结构模型顶部,开展了风洞试验。试验结果表明,TL-PD在颗粒充分碰撞后对高层结构具有良好的振动控制效果,且控制效率受到质量比、颗粒密度及风速的影响。     

TLD控制的钢结构振动台模型试验研究

本文通过钢结构的振动台模型试验,研究了在刚性地基条件下矩形调谐流体阻尼器(TLD)对结构地震反应的减震机理和减震效果,为进一步研究土-结构相互作用对结构TLD减震控制效率影响的振动台模型试验提供对比数据。试验结果表明,在水箱中设置铁丝网有助于提高TLD的减震效率,地震动的频谱特性和峰值加速度大小对TLD的减震效率有重要影响。     

调谐液体减振器的减振作用分析

本文以水箱-结构体系为对象,研究了调谐减振器的减振作用,肯定了它的减振效果,对其减振效果与液体自振频率、液深等因素的关系进行了分析。在本文中水箱的计算模型是三维的,液体用半解析单元离散,结构为一多自由度体系。本文计算模型的自由度数目较一般有限元法大大减少。     

磁流变调谐液柱阻尼器半主动地震反应控制研究

结构的半主动控制装置是国际上研究的一个热点.磁流变式调谐液柱阻尼器(MR-TLCD)是一种新型的减振驱动器.文中提出了抑制结构水平振动的MR-TLCD模型,建立了MR-TLCD与结构相互作用的运动方程.在经典线性最优控制(COC)和瞬时最优控制(IOC)算法的基础上,研究了Clipped-optimal半主动控制策略的减振效果,并与被动控制的减振效果进行了对比.结果表明:磁流变式调谐液柱阻尼器的半主动控制能够有效地减小结构的地震反应,且优于被动控制.     

基于黏滞液体阻尼器的铁路钢桁梁桥减震研究

以某高墩大跨度铁路简支钢桁梁桥为实际工程背景,研究了黏滞液体阻尼器对结构纵向抗震性能的影响.采用非线性时程分析方法,对黏滞液体阻尼器的相关参数及布置位置进行了优化分析.分析结果表明:合理选择黏滞液体阻尼器的布置位置、个数及阻尼参数,高墩大跨铁路简支钢桁梁桥具有明显的减震效果.     

斜拉桥纵向设置粘滞阻尼器参数分析

采用Maxwell阻尼模型模拟了粘滞阻尼器的滞回耗能特性。通过对设置粘滞阻尼器斜拉桥纵向非线性地震反应的分析，讨论了粘滞阻尼器各参数对结构地震响应的影响，并通过计算证实了粘滞阻尼器具有良好的消能减振效果。     

A Monte Carlo study of rainfall forecasting with a stochastic model

A procedure for short-term rainfall forecasting in real-time is developed and a study of the role of sampling on forecast ability is conducted. Ground level rainfall fields are forecasted using a stochastic space-time rainfall model in state-space form. Updating of the rainfall field in real-time is accomplished using a distributed parameter Kalman filter to optimally combine measurement information and forecast model estimates. The influence of sampling density on forecast accuracy is evaluated using a series of a simulated rainfall events generated with the same stochastic rainfall model. Sampling was conducted at five different network spatial densities. The results quantify the influence of sampling network density on real-time rainfall field forecasting. Statistical analyses of the rainfall field residuals illustrate improvement in one hour lead time forecasts at higher measurement densities.     

Earthquake Engineering and Engineering Vibration Aims And Scope

正This journal is established by the Institute of Engineering Mechanics(IEM),China Earthquake Administration,to promote scientific exchange between Chinese and foreign scientists and engineers so as to improve the theory and practice of earthquake hazards mitigation,preparedness,and recovery.To accomplish this purpose,the journal aims to attract a balanced number of papers between Chinese and     

Foreword

Destructive earthquakes have caused great damage in China and the United States and collapsing buildings havecaused many deaths and injuries. The field of earthquake engineering studies earthquake hazards, the occurrence ofearthquakes of various magnitudes, the nature of the ground shaking during an earthquake, the vibration of structuresduring earthquakes, the strengthening of existing structures and the design of new structures to be earthquake resistant,and finally, how to cope with earthquake damage and restore a city to normal functioning. Such efforts are in progressin both countries, but unfortunately, the language barrier interferes with the free flow of information between China andthe Untied States. It would be mutually beneficial if some means could be developed to promote the exchangeof information across the Pacific Ocean. This new journal has been established for this purpose and its success willbe an important step in promoting earthquake engineering in China and the United States.     

WORLD ASSOCIATION FOR SEDIMENTATION AND EROSION RESEARCH(WASER)

正President:Giampaolo Di Silvio,Italy Vice Presidents:Ulrich C.E.Zanke,Germany Zhao-yin Wang,China The World Association for Sedimentation and Erosion Research(WASER),inaugurated on Oct.19,2004,is an independent non-governmental,non-profit organization.The mission of WASER is to promote international co-operation on the study     

Enhancing remote sensing research on global change to improve our understanding on Earth system processes

正Global Change includes climate change and other environmental changes caused by the joint interaction among various layers of Earth. From the positive side, global change provides new opportunities to human and other living forms on Earth. In the meantime, it creates tremendous challenges and negative impact. At present, the negative impacts have reached all primary processes of the global ecosystem and every aspect of human society, especially causing degradation of the ecosystem. For instance, intensive deforestation causes decline of biodiversity; global warming causes sea level rise and increases