双环软钢耗能器的试验研究

本文提出了“利用两个或多个耗能元件协同工作,同时耗能来设计新型耗能器”的思想,研究设计了双环软钢耗能器,并对三种不同构造的双环软钢耗能器进行了循环加载试验,考察了耗能器的工作特性和耗能性能,揭示了耗能的机理,给出了耗能器的恢复力模型。研究结果表明,双环软钢耗参器是一种初始刚度和屈服力高、变形性能好、耗能能力强、工作性能稳定、构造简单、制作与安装方便的新型耗能减震装置,具有广阔的应用前景。     

圆环耗能器的试验研究

对软钢圆环耗能器进行了低周反复荷载试验和分析，考察了圆环耗能器的工作特性和耗能性能，揭示了圆环耗能器的耗能机理和规律，并通过对不同设计参数圆环耗能器的对比试验，考查了设计参数对圆环耗能器性能的影响，提出了改进方案。     

加劲圆环耗能器性能的试验研究

本文提出了“耗能器应具有多道耗能减震防线”的思想,研究了设计了国圆环耗能器,并对其进行了循环加试验,考察了耗能器的工作用耗能性能。     

两种摩擦耗能器的比较试验研究

对两种不同形式的摩擦耗能器进行了低周反复荷载试验。工其工作性能和耗能性能，并进行了带有不同摩擦片和不带摩擦片的对比试验，分析了影响耗能器性能的因素，试验结果表明，摩擦耗能支撑具有稳定的滞回性能和极好的耗能能力，摩擦片的类型与性能对摩擦耗能支撑的性能有较大的影响。     

耗能减震结构的抗震设计原则与设计方法

根据国内外耗能减震器和耗能减 研究成果,结合我国正在修订的建筑结构抗震设计规范,提出了耗能减震结构的实用抗震设计方法。     

工字型钢铅组合耗能器的非线性有限元模拟

钢铅组合耗能器将钢和铅2种材料巧妙地进行组合,具有制作工艺简单、经济性好等优点。在一种工字型钢铅组合耗能器试验研究的基础上,借助有限元分析软件ANSYS,考虑钢和铅2种材料本构模型的非线性以及2种材料之间的接触作用,建立了这种耗能器的非线性有限元计算模型,对耗能器进行数值模拟;在此基础上对安装耗能器的Benchmark结构进行了地震反应分析。研究结果表明建立的有限元模型能够准确描述耗能器的力学性能,耗能器具有良好的滞回性能和稳定的耗能特性,是一种优良的耗能元件;工字型钢铅组合耗能器减震效果明显。     

新型SMA耗能器及结构地震反应控制试验研究

利用NiTi合金丝的超弹性性能，本文提出了两种新型SMA被动耗能器，分别称之为拉伸型SMA耗能器和剪刀型SMA耗能器。通过对耗能器的构造设计，安装在耗能器中的NiTi丝始终处于受拉状态，避免了合金丝在结构振动过程中受压屈曲。文中阐述了拉伸型SMA耗能器和剪刀型SMA耗能器的构造及工作原理，并将其安装在模型结构上进行了地震模拟振动台试验，验证了新型SMA耗能器的减振效果。     

钢屈服—摩擦复合耗能器的性能研究

本文提出了“综合利用不同耗能原理和机制来设计新型耗能器”的思想,研究开发了钢屈服－摩擦复合耗能器,并对其进行了性能试验和对比试验,考察了耗能器的工作性能和耗能性能。给出了耗能器的恢复力模型,研究结果表明,钢屈服－摩擦复合耗能器利用钢屈服滞回和摩擦两种机制耗能,具有稳定的工作性能,耗能能力强且可调节,构造简单,形状紧凑,体积小,造价低,制作与安装方便,是一种有广阔应用前景的新型耗能减震装置。     

组合钢板耗能器—一种新型耗能减震装置

本文在吸收普通钢板耗能器和Ｐａｌｌ摩擦耗能器优点的基础上提出了组合钢板耗能器，建立了相应的力学分析和计算模型；通过地震反应分析检验了其减振效果，并与普通钢板耗能器进行了对比。研究结果表明，组合钢板耗能器是一种构造简单，耐久性好，减效果和经济效果俱佳的抗震效果，具有广阔手应用前景。     

耗能减震技术研究及应用的新进展

本文总结了耗能减震技术近年来的研究与应用情况,主要包括各种新型耗能减震装置的原理、性能及应用。文中介绍了有关国家耗能减振技术标准发展的情况,提出了该项技术今后应加强研究的若干问题,并预测了其发展前景。     

消能支撑框架结构的非线性分析

本文介绍了六榀钢筋混凝土支撑框架模型（两榀为普通支撑框架，另四榀为消能支撑框架）在低周反复荷载作用下的工作性能和试验结果；编制了非线性程序，对试验模型进行了计算分析，计算结果和试验实测值符合较好；另外还计算了两榀足尺消能支撑框架结构，研究不同的消能器滑移荷载对结构抗震能力的影响，结果表明消能支撑框架结构具有良好、稳定的抗震性能。     

铅挤压消能支撑框架模型结构试验研究

通过铅挤压消能器的低周反复加载试验,以及安装有铅挤压消能器的钢筋混凝土消能支撑框架模型结构的伪静力试验,主要研究了铅挤压消能器单独受反复荷载时的消能性能以及其在模型结构中所起的消能作用,模型结构的破坏机理和整体消能能力。研究结果表明,铅挤压消能器具有很好的消能能力,在模型结构总耗能中占据了很大的比例,模型结构具有较好的耗散地震能量的能力。     

薄弱层设置耗能阻尼器支撑的钢框架模型振动台试验

设计制作了一个五层钢框架模型,在其第一层、第三层和第五层薄弱层分别设置摩擦阻尼器、粘弹性阻尼器和粘弹性-摩擦阻尼器等三种耗能阻尼器支撑,进行了罕遇地震和多遇地震下的振动台试验。试验结果表明,耗能阻尼器支撑能够有效地控制结构的地震反应。     

Discussion of ‘Modelling viscous damping in nonlinear response history analysis of buildings for earthquake excitation’ by Anil K. Chopra and Frank McKenna

This discussion deals with recommendations in the paper on appropriate damping formulations for use in nonlinear response history analysis of buildings. Concern over potentially excessive damping forces and moments should extend beyond the damping moments produced by the stiffness proportional part of Rayleigh damping that corresponds to rotational springs used to explicitly model plastic hinges. The key to an appropriate damping formulation for nonlinear analysis is a realistic mechanism that allows all damping forces and moments to be meaningfully assessed. Then features can be added to keep these forces and moments within reasonable bounds. Copyright © 2016 John Wiley & Sons, Ltd.     

A two‐step direct method for estimating the seismic response of nonlinear structures equipped with nonlinear viscous dampers

The insertion of fluid viscous dampers in building structures is an innovative technology that can improve significantly the seismic response. These devices could be very useful also in the retrofit of existing buildings. The effect of this typology of damping system is usually identified with an equivalent supplemental damping ratio, which depends on the maximum displacement of the structure, so that iterative procedures are required. In this paper, a simplified direct assessment method for nonlinear structures equipped with nonlinear fluid viscous dampers is proposed. The method proposed in this study is composed by two steps. The first one yields the direct estimate of the supplemental damping ratio provided by nonlinear viscous dampers in presence of a linear elastic structural response. The second step extends the procedure to structures with nonlinear behavior. Both graphical and analytical approaches have been developed. The proposed method has then been verified through several applications and comparisons with nonlinear dynamic analyses. Moreover, an investigation has been performed with regard to the influence of the relations that define the damping reduction factor and the hysteretic damping. Copyright © 2014 John Wiley & Sons, Ltd.     

Response prediction,experimental characterization and P‐spectra design of frames with viscoelastic–plastic dampers

Viscoelastic–plastic (VEP) dampers are hybrid passive damping devices that combine the advantages of viscoelastic and hysteretic damping. This paper first formulates a semi‐analytical procedure for predicting the peak response of nonlinear SDOF systems equipped with VEP dampers, which forms the basis for the generation of Performance Spectra that can then be used for direct performance assessment and optimization of VEP damped structures. This procedure is first verified against extensive nonlinear time‐history analyses based on a Kelvin viscoelastic model of the dampers, and then against a more advanced evolutionary model that is calibrated to characterization tests of VEP damper specimens built from commercially available viscoelastic damping devices, and an adjustable friction device. The results show that the proposed procedure is sufficiently accurate for predicting the response of VEP systems without iterative dynamic analysis for preliminary design purposes. A design method based on the Performance Spectra framework is then proposed for systems equipped with passive VEP dampers and is applied to enhance the seismic response of a six‐storey steel moment frame. The numerical simulation results on the damped structure confirm the use of the Performance Spectra as a convenient and accurate platform for the optimization of VEP systems, particularly during the initial design stage. Copyright © 2016 John Wiley & Sons, Ltd.     

新型粘弹性阻尼器在震害下的力学分析

粘弹性阻尼器是有效的被动消能装置,普通粘弹性阻尼器的力学性能主要受环境温度、激励频率和应变幅值的影响,对结构的设计结果会产生偏差.新型粘弹性阻尼材料,其力学性能不受环境温度和激励频率的影响,通过与普通粘弹性阻尼器动态力学性能的对比,可见新型粘弹性阻尼器作为耗能元件,对消能减震结构的设计结果会比较精确.     

Elemental damping formulation: an alternative modelling of inherent damping in nonlinear dynamic analysis

To date, nonlinear dynamic analysis for seismic engineering predominantly employs the classical Rayleigh damping model and its variations. Though earlier studies have identified issues with the use of this model in nonlinear seismic analysis, it still remains the popular choice for engineers as well as for software providers. In this paper a new approach to modelling damping is initiated by formulating the damping matrix at an elemental level. To this regard, two new elemental level discrete damping models adapted from their global counterparts are proposed for its application in nonlinear dynamic analysis. Implementation schemes for these newly proposed models using Newmark incremental method and revised Newmark total equilibrium method is outlined. The performance of these proposed models, compared to existing models, is illustrated by conducting nonlinear dynamic analyses on a four story RC frame designed to Eurocodes. The incremental dynamic analysis study presented in the paper illustrates the fact that both the proposed models seem to produce more reliable results from an engineering perspective in comparison to the global models. It is also shown that the proposed elemental damping models lead to smaller and more realistic damping moments in the plastic hinges. Furthermore, these models could be easily included in existing software frameworks without adding noticeably to the computational effort. The computation time required for these models is approximately equivalent to the one required when using the tangent Rayleigh damping matrix with constant coefficients.     

Seismic response of arch dams considering infinite radiation damping and joint opening effects

Effects of two important factors on earthquake response of high arch dams are considered and combined into one program. These factors are: effects of radiation damping of the infinite canyon and local non-linearity of the contraction joint opening between the dam monoliths. For modeling of rock canyon, the discrete parameters are obtained based on a curve fitting, thus allowing the nonlinear dam system to be solved in the time domain. The earthquake uniform free-field input at the dam-canyon interface is used. An engineering example is given to demonstrate the significant effects of the radiation damping on the structure response.     

Inelastic response of RC frame buildings with seismic isolation

A comprehensive parametric study on the inelastic seismic response of seismically isolated RC frame buildings, designed for gravity loads only, is presented. Four building prototypes, with 23 m × 10 m floor plan dimensions and number of storeys ranging from 2 to 8, are considered. All the buildings present internal resistant frames in one direction only, identified as the strong direction of the building. In the orthogonal weak direction, the buildings present outer resistant frames only, with infilled masonry panels. This structural configuration is typical of many existing RC buildings, realized in Italy and other European countries in the 60s and 70s. The parametric study is based on the results of extensive nonlinear response‐time history analyses of 2‐DOF systems, using a set of seven artificial and natural seismic ground motions. In the parametric study, buildings with strength ratio (F_y/W) ranging from 0.03 to 0.15 and post‐yield stiffness ratio ranging from 0% to 6% are examined. Three different types of isolation systems are considered, that is, high damping rubber bearings, lead rubber bearings and friction pendulum bearings. The isolation systems have been designed accepting the occurrence of plastic hinges in the superstructure during the design earthquake. The nonlinear response‐time history analyses results show that structures with seismic isolation experience fewer inelastic cycles compared with fixed‐base structures. As a consequence, although limited plastic deformations can be accepted, the collapse limit state of seismically isolated structures should be based on the lateral capacity of the superstructure without significant reliance on its inherent hysteretic damping or ductility capacity. Copyright © 2012 John Wiley & Sons, Ltd.