约束阻尼层在钢桁架振动控制中的应用

讨论了应用约束阻尼层在钢桁架结构中的减振问题,首先给出了粘弹性阻尼材料的基本力学特性和约束阻尼层的两种有限元建模方法,通过ANSYS对一约束阻尼结构采用两种不同的有限元模型进行数值仿真分析比较,给出了在ANSYS中准确模拟这类结构的途径,应用这一建模方法对一钢桁架塔柱安装约束阻尼层减振方案的减振效果进行了数值仿真,计算结果表明,安装约束层后结构前两阶弯曲模态阻尼比有较大提高,但扭转模态的模态阻尼比提高很少,约束阻尼层对钢桁架结构弯曲振动控制效果良好。     

电涡流TMD阻尼特性的有限元模拟与参数优化

调谐质量阻尼器(TMD)在人行桥、大跨楼板等结构的竖向振动控制中有着较为广泛的应用。传统的TMD采用硅油作为阻尼单元,这不但会带来施工不便、耐久性差、阻尼难以调节等问题,而且硅油还会给TMD带来附加刚度,造成频率的失调。利用电涡流阻尼代替硅油,提出了一种新型的电涡流TMD,并利用大型电磁场有限元分析软件Opera3D对其进行建模分析。对永磁铁布置方式、导体板厚度和导磁板厚度进行了参数优化分析,结果表明:永磁铁布置方式对电涡流阻尼有较大的影响;电涡流阻尼随着导体板、导磁板厚度的增加呈非线性增长。最后,对经优化设计的磁路进行电涡流阻尼与磁导间距间关系的分析与公式拟合,并提出了一种有较强适用性的电涡流TMD设计方法。     

附加电涡流阻尼TMD的高层建筑结构振动台试验研究

电涡流阻尼系统(Eddy-Current System)是一种广泛应用在机械工程和航空航天领域的减振控制技术,将电涡流阻尼系统与传统的调谐质量阻尼器(Tuned Mass Damper,TMD)相结合而成的新型电涡流阻尼TMD(EC-TMD)在土木工程中的应用还处于起步阶段。通过附加电涡流阻尼TMD的五层钢框架结构振动台试验,考察了该装置对高层建筑结构的减振控制效果。试验结果表明:附加电涡流阻尼TMD可以明显减少主体结构的加速度、位移、最大层间位移角等响应;电涡流阻尼TMD的控制效果受输入激励特性的影响,也和本身的质量比、电涡流阻尼比有关;与传统TMD相比,电涡流阻尼TMD可以更快速的抑制结构振动,并能将自身摆幅控制在较小范围内。     

钢板夹层阻尼高频TMD两阶段设计方法

随着工业化的发展,建筑结构逐渐轻量化,机械设备逐渐重型化、高效化,这使得机械设备高频扰力导致的结构振动问题越来越突出;为了减轻结构的高频受迫振动响应,可以在结构振动响应较大的位置安装高频高阻尼比的钢板夹层阻尼悬臂梁式调谐质量阻尼器(tuned mass damper,TMD).由于TMD的弹性元件与阻尼元件相互耦合,因...     

建筑结构粘弹性阻尼耗能研究

本文探讨了建筑结构的粘弹性动力特性,提出了一种对高层建筑结构振动下粘弹性动力特性进行分析的方法,并对分析结果进行机理分析。这些工作为阻尼材料在工程中的应用建立分析计算基础。     

粘弹性阻尼结构的振动台试验

本文通过对一１：５装有粘弹性阻尼器的三层钢筋混凝土框架结构模型进行振动台试验,了解粘弹性阻尼结构的动 力特性和破坏情况。并对比研究了加与未加粘弹性阻尼器结构的动力反应试验结果,以及加有粘弹性阻尼器结构的试验 和弹塑性分析结果,得出有关结论。     

粘弹性阻尼器在钢混框架结构中的优化布置

粘弹性阻尼器是结构消能减震中一种有效的被动控制装置。文中建立12层的钢筋混凝土框架模型,对比了三种粘弹性阻尼器的优化布置方案。分析结果对粘弹性阻尼在实际工程中设计优化有一定的指导意义。     

地震作用下复阻尼调频质量阻尼器减震结构优化设计

分析了简谐激励和平稳随机激励条件下,复阻尼调频质量阻尼器(TMD)和主结构的二自由度减震结构体系的稳态地震响应,建立了动力学平衡方程,推导了复阻尼TMD的阻尼和频率最优参数的理论公式,并分析了该二自由度减震结构体系在多条地震波作用下的减震效果,对比了复阻尼TMD和粘滞阻尼TMD减震效果的差异,结果表明:复阻尼TMD的减震效果接近于粘滞阻尼TMD的结果,在应用TMD减震技术时,复阻尼TMD也是一种选择。     

钢框架结构阻尼耗能的分析研究

文章通过钢框架结构中设置耗能阻尼支撑、阻尼器以及粘弹性阻尼墙,通过已有的有限元程序分析数据进行对比,得出每一种阻尼耗能的特点以及适用范围。分析得出,在钢框架中设置粘弹性墙,其主体结构的耗能能力增加最为明显;在钢框架中加入阻尼器,可以有效的改善钢框架对地震作用的响应值;钢框架通过设置构造简单的耗能阻尼支撑,其消耗地震能量的作用也较为明显,其中八字型耗能阻尼支撑的耗能能力优于V型和D型耗能阻尼支撑。     

粘弹性阻尼墙的理论分析

粘弹性阻尼墙是一种性能良好的消能减震部件。文章从粘弹性阻尼墙的构造出发,利用Ansys有限元软件,对照普通粘弹性阻尼器进行粘弹性阻尼墙的理论分析。     

Robust control of plate vibration via active constrained layer damping

In this paper, the theoretical modeling of a plate partially treated with active constrained layer damping (ACLD) treatments and its vibration control in an H_∞ approach is discussed. Vibration of the flat plate is controlled with patches of ACLD treatments, each consisting of a viscoelastic damping layer which is sandwiched between the piezo-electric constrained layer and the host plate. The piezo-electric constrained layer acts as an actuator to actively control the shear deformation of the viscoelastic damping layer according to the vibration response of the plate excited by external disturbances. In the first part of this paper, the Mindlin–Reissner plate theory is adopted to express the shear deformation characteristics of the viscoelastic damping layer, meanwhile GHM (Golla–Hughes–McTavish) model of viscoelastic damping material and FEM (finite element model) are incorporated to describe the dynamics of the plate partially treated with ACLD treatment. In the second part, particular emphasis is placed on the vibration control of the first four modes of the treated plate using H_∞ robust control method. For this purpose, an H_∞ robust controller is designed to accommodate uncertainties of the ACLD parameters, particularly those of the viscoelastic damping core which arise from the variation of the operation temperature and frequency. Disturbances and measurement noise are rejected in the closed loop by H_∞ robust controller. In the experimental validation, external disturbances of different types are employed to excite the treated plate. The results of the experimental clearly demonstrate that the proposed modeling method is correct and the ACLD treatments are very effective in fast damping out the structural vibration as compared to the conventional passive constrained layer damping (PCLD).     

某生产楼TMD减振系统的应用分析研究

简单介绍了TMD减振系统的原理.针对某生产楼在生产运行过程中楼板的明显振感,对生产楼进行振动检测,通过鉴定结论提出将TMD减振系统应用到该生产楼,并结合ANSYS谐响应分析提出该生产楼最优TMD减振系统应用方案.     

常摩擦TMD特性和简谐激励控制效果的研究

摩擦TMD用摩擦阻尼替代传统的粘滞阻尼,可有效降低成本,促进其推广应用,但摩擦阻尼的非线性给摩擦TMD分析和设计造成了一定的困难。本文首先对常摩擦单自由度系统的自由振动和强迫振动特点在时域和频域内进行了分析,然后从理论和试验两方面分析了常摩擦TMD在简谐激励下对单自由度主结构响应的控制效果。结果表明,常摩擦TMD系统存在停顿现象,参数设置合理,TMD能启动的情况下,其简谐激励控制效果令人满意。     

阻尼夹层板的振动特性分析

为考察阻尼夹层板能否有效而经济地减小厂房的振动,本文从理论上建立了阻尼夹层板的振动方程,并由此分析结构参数变化对板减振效果的影响.本文结论对实际工业厂房减振设计具有一定的参考价值.     

Active/passive control of sound radiation and power flow in fluid-loaded shells

The vibration and noise radiation from fluid-loaded cylindrical shells are controlled by using multiple stiffeners and passive constrained layer damping treatment. Dynamic and fluid finite elements are developed to study the fundamental phenomena governing the coupling between the stiffened shell, with and without damping, and the fluid domain surrounding it. The models are used to predict the response of the shell and to evaluate the effect of stiffening rings and damping treatment on both the structural vibration and noise radiation in the fluid domain. The geometry of the shell and fluid domain allows the formulation of a harmonic-based model, which uncouples the fluid–structural response of modes corresponding to different numbers of circumferential nodes.In this study, it is shown that stiffening of the shell reduces the amplitude of the vibration and noise radiation, particularly for high-order lobar modes. The attenuation of the shell response and sound radiation can be increased significantly through the application of passive constrained layer damping treatments on the inner surface of the stiffening rings.     

SH波作用下粘弹性半空间场地土地震反应分析

本文考虑稳态简谐SH波激励下的谐和振动和场地土的材料阻尼,建立弹性动力反平面应变模型,采用一维粘弹性波动理论进行土层地震反应分析,得出基岩运动输入下半空间上覆粘弹性场地土体系的解析解.利用此解来分析SH波激励下粘弹性场地土动力效应,讨论不同场地土的动力特性参数对粘弹性场地土动力效应的影响.土-结构物动力相互作用和材料阻尼对场地土地震反应有很明显的影响,这为工程中的地震场地效应评价、震害分析和结构抗震设计都提供一定的参考依据.     

Control of axi-symmetric vibrations of cylindrical shells using active constrained layer damping

Distributed-parameter modeling of thin cylindrical shells which are fully treated with active constrained layer damping (ACLD) is presented. Hamilton's principle is utilized to develop the shell/ACLD model as well as the associated boundary conditions. A globally stable boundary control strategy is developed to damp out the vibration of the shell/ACLD system. The devised boundary controller is compatible with the operating nature of the ACLD treatments where the strain induced, in the active constraining layer, generates a control force acting at the boundary of the treated shell. As the boundary control strategy is based on a distributed-parameter model of the shell/ACLD system, the classical spillover problems resulting from using “truncated” finite element models is eliminated. Also, such an approach makes the boundary controller capable of controlling all the modes of vibration of the shell/ACLD and guarantees that the total energy norm of the system is continuously decreasing with time. Numerical examples are presented to demonstrate the effectiveness of the ACLD in damping out the vibration of cylindrical shells. Such effectiveness is determined for different control gains and compared with the performance of conventional passive constrained layer damping (PCLD). The results obtained demonstrate the high damping characteristics of the boundary controller particularly over broad frequency bands.     

某高层结构长悬臂钢框架楼板的减振分析

本文采用有限元软件ETABS对人行走激励下高层长悬臂钢框架楼板进行TMD减振分析。根据节点加速度、弹簧力和阻尼力等计算结果,表明合理的TMD布置方式和参数选取可有效控制长悬臂钢框架楼板竖向振动,改善竖向舒适度。