【作者】 钱辉；

【导师】 李宏男； 宋钢兵；

【作者基本信息】 大连理工大学 ， 防灾减灾工程及防护工程， 2008， 博士

【摘要】 结构振动控制是已经被实际工程证明了的能够改善结构抗震性能、减小结构地震反应的积极有效方法。其中,被动消能减震因其构造简单、造价低廉、易于维护且无需外部能源支持等优点,成为目前发展较为成熟且工程中得到广泛应用的振动控制技术。然而,目前开发的耗能器存在着一些缺点,如材料的老化和耐久性、残余变形以及大震过后的更新替换等问题。近年来,智能材料和控制装置的研究和发展为土木工程结构减震控制开辟了新的天地,为新一代高性能被动耗能器的研制和开发提供了基础。形状记忆合金(Shape Memory Alloys,简称SMA)是一种新型的智能材料,因其独特的形状记忆效应、超弹性、高阻尼和耐腐蚀特性,成为土木工程结构消能减震的理想材料。本文在超弹性SMA丝的力学性能、超弹性SMA的本构模型、新型SMA阻尼器的研制开发及性能测试、SMA阻尼器消能减震结构体系的参数优化及非线性分析、SMA阻尼器进行结构震动控制的振动台试验等方面进行了深入系统的研究,主要内容包括:(1)试验研究了三种直径超弹性NiTi SMA丝的力学特性,考察了循环加载次数、加载速率、应变幅值和环境温度对其力学性能(相变应力、每循环耗散能量、割线刚度、等效阻尼比和残余应变等)的影响,揭示了加卸载过程中因潜热引起的SMA丝温度的变化规律,为SMA阻尼器设计中材料的选择提供了试验基础。(2)提出了超弹性SMA的改进本构模型。在试验的基础上,针对Graesser &Cozzarelli模型不能描述马氏体硬化效应和应变率相关特性的缺点,提出了改进的Graesser & Cozzarelli模型,给出了模型参数选取原则和方法,并通过数值仿真结果和试验结果的对比,验证模型了的适用性。(3)开发研制了新型筒式自复位SMA阻尼器(TRSMAD)。采用超弹性SMA丝提出了一种筒式自复位SMA阻尼器,试验研究了SMA丝初始应变、位移幅值和加载频率对阻尼器力学性能的影响,建立了阻尼器一维理论模型,并对其力学性能进行了数值模拟。(4)开发研制了新型复合型SMA摩擦阻尼器(HSMAFD)。采用超弹性SMA丝自复位装置和摩擦耗能装置,提出了一种复合型SMA摩擦阻尼器,该阻尼器有效利用摩擦装置的高耗能和SMA的自复位功能,具有更强的耗能能力;试验测试了SMA丝初始应变、摩擦力、位移幅值及加载频率对阻尼器力学性能的影响,建立了阻尼器的理论模型,并对其力学性能进行了数值模拟。(5)研究了SMA阻尼器结构振动控制的参数优化及非线性分析问题。采用能量平衡分析方法对SMA消能减震结构体系阻尼器的参数进行了优化,给出了阻尼器参数的建议取值范围。建立了安装SMA阻尼器的对称结构和偏心结构在地震作用下的运动方程,并基于MATLAB语言编写了SMA阻尼器消能减震结构体系的弹塑性时程分析程序。最后,分别以多层对称框架结构和偏心框架结构为算例,对SMA阻尼器消能减震结构体系在地震作用下的反应进行了数值分析,验证了SMA阻尼器的减震效果。(6)进行了对称结构的振动台试验,以验证SMA阻尼器对结构平移震动反应的控制效果。设计了一个三层对称钢框架模型,分别将两种新型阻尼器安装在结构底层的质心位置,对无控条件下和安装阻尼器的有控条件下的结构反应进行了振动台试验,并通过能量分析方法对SMA阻尼器消能减震体系的能量分配进行了评价。结果表明,SMA阻尼器可以有效抑制结构的平动反应。(7)进行了偏心结构的振动台试验,以验证SMA阻尼器对结构平-扭耦联震动反应的控制效果。设计了一个三层单向偏心的钢框架模型,分别将两种新型阻尼器安装在结构底层的一侧,并通过振动台试验,分别对无控条件下和安装阻尼器的有控条件下的结构反应进行了研究。结果表明,SMA阻尼器可以有效抑制结构的平-扭耦联震动反应。更多还原

【Abstract】 Structural vibration control is an effective design strategy to enhance structural performance against earthquake and mitigate seismic response,which has been verified in the practical engineering.Passive energy dissipation is a comparative mature technology which has been widely used in earthquake engineering due to its simple configuration,low cost,easy maintenance and reliable run without power support.However,current technologies present some limitations,such as problems related to aging and durability,residual displacement, substitution after strong events,among others.Recently,the increasing research and development of smart materials and controlling devices open up a new area for seismic vibration control of structural engineering,providing a basic platform for the design and exploration of new generation high-performance passive damping devices.Shape memory alloys(SMA) are a class of novel smart materials that possess unique properties,including shape memory effect,superelasticity effect,extraordinary fatigue resistance,high corrosion resistance and damping characteristics,which make them perfect candidates for seismic energy dissipation devices in structural engineering.This thesis focuses on the use of superelastic SMA-based energy dissipation system for structural vibration control.Extensive investigations on the mechanical behavior of superelastic SMA wires by cyclic tensile tests,improvement of the constitutive model for superelastic SMA,design and performance test of innovative SMA dampers,analysis and optimization of energy dissipation system based on SMA damper and structural vibration control using SMA damper subjected to earthquakes,are carded out.The main contents are included as follows:(1) Cyclic tensile tests on superelastic NiTi SMA wires with three diameters were carried out.The effects of the different loading conditions,namely:cyclic loading-unloading number, strain amplitude,loading frequency and ambient temperature,on the mechanical behavior described by some fundamental quantities,such as energy dissipation per cycle,secant stiffness,equivalent damping,residual strain,were examined.The temperature changes of the SMA wires due to the latent heat under different loading conditions are analyzed.(2) According to the test data,a novel constitutive model of superelastic SMAs based on the Graesser and Cozzarelli’s model is proposed,which is capable of describing the martensitic hardening under large amplitudes and the strain-rate dependent hysteretic behavior at different strain levels.An iterative procedure to determine parameter values of the improved model is proposed.To verify the effectiveness of the proposed constitutive model, comparisons between experimental and numerical results predicted by the proposed model were conducted.(3) An innovative telescopic recentering SMA damper(TRSMAD) was proposed by utilizing both the high damping and recentring features of superelastic SMA wire.The mechanical behaviors of the damper under various cyclical loading-unloading conditions with different pre-strain,displacement amplitude and loading rate were investigated experimentally. One-dimensional theoretical model based on plastic theory for TRSMAD was developed and the numerical simulation for the mechanical behaviors of the damper was performed by means of the developed model.(4) An innovative hybrid shape memory alloy friction device(HSMAFD) which consists of pre-tensioned superelastic SMA wires and friction devices(FD) was proposed.The most important property of the HSMAFD is the integration and unification with stable large energy dissipation capacity provided FD and re-centering feature profited from the superelastic pre-tensioned SMA wires.To investigate the mechanical behaviors of the damper as a function of pre-displacement,displacement amplitude,friction force and loading frequency, cyclic tensile tests on a scale model under various loading conditions were conducted.The theoretical model for HSMAFD was developed and the numerical simulation for the mechanical behaviors of HSMAFD was conducted.(5) The optimization of the parameters as well as nonlinear analysis of the energy dissipation system with SMA dampers was performed.Using energy balance method,the parameters of the SMA damper-based energy dissipation system were optimized,and the reasonable value ranges for the parameters were suggested.The dynamic equations of the symmetrical and eccentric structures with SMA dampers under earthquakes were developed and nonlinear time history analysis program for the energy dissipation system with SMA dampers based on MATLAB software was compiled.Then,as examples,two SMA damper-based frame buildings with or without eccentricity subjected to earthquake ground motions were analyzed to assess the effectiveness of the SMA dampers in reducing the structural seismic response.(6) Shaking table tests on a reduced-scale symmetric steel frame model with and without SMA dampers were carried out to verify the effectiveness of the SMA damper-based energy dissipation system in reducing translational response of structures subjected to strong seismic excitations.A 1/4-scale,3-story symmetric steel frame model of building was designed.One TRSMAD and HSMAFD were installed in the bottom story of the model,respectively.The building model with and without SMA dampers were tested through shake table.The energy analysis method was also utilized to evaluate the distribution of energy for the energy dissipation system.The experimental results show that the SMA dampers can effectively suppress the translational response of symmetric buildings.(7) To verify the control effect of SMA dampers in reducing torsion coupled response of eccentric buildings,shaking table tests on a reduced-scale eccentric steel frame model with and without SMA dampers were performed.A 1/4-scale,3-story steel frame model of building with eccentricity was designed.One TRSMAD and HSMAFD were installed in the bottom story of the model,respectively.The building model with and without SMA dampers were tested through shake table.The experimental results indicate that the SMA dampers can effectively reduce the torsion coupled response as well as translational vibration of symmetric buildings.更多还原