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类型 基础研究 预答辩日期 2018-03-08
开始(开题)日期 2015-12-21 论文结束日期 2017-11-23
地点 逸夫建筑馆707室 论文选题来源 国家自然科学基金项目     论文字数 12.9 (万字)
题目 新型预拉杆式自定心BRB结构的抗震性能与设计方法
主题词 自定心屈曲约束支撑,抗震性能,非线性位移比,残余位移比,抗震设计方法
摘要 预拉杆式自定心屈曲约束支撑(Self-centering Buckling-Restrained Brace, SC-BRB)具有良好的耗能能力和自定心性能,能够有效提高结构的震后可修复性。已有的SC-BRB构造在强地震作用下,预拉杆仍可能屈服甚至断裂从而影响结构的可修复性和安全性。同时,当预拉杆无法满足结构变形需求或相邻抗弯框架屈服时,均会导致结构产生一定的残余变形,而目前SC-BRB框架基于性能的设计方法仅考虑最大变形,未将残余变形纳入设计性能目标,难以确保结构震后的可修复性。 针对上述问题,本文进行了如下工作。 (1) 提出增大支撑变形能力和提高初始刚度可控性的新型预拉杆式SC-BRB的概念与构造。针对现有SC-BRB对预拉杆的弹性延伸率需求较高,和套管长度加工误差会显著改变支撑初始刚度的问题,分别给出相应改进措施,建立了新型预拉杆式SC-BRB的概念,提出增大支撑变形能力的措施(摩擦保险装置或串联式SC-BRB)和提高支撑初始刚度可控性的措施(橡胶夹层端板),深入分析其工作机理和力学行为,并建立适用于新型预拉杆式SC-BRB构件的构造设计方法和设计流程。 (2) 预拉杆和摩擦保险装置的性能试验研究。对玄武岩纤维筋(Basalt Fiber-Reinforced Polymer, BFRP)预拉杆和摩擦保险装置进行性能试验,结果表明:BFRP筋的极限延伸率超过2.5%,且性能较为稳定,但预拉杆循环拉伸时会由于锚具中的锚固胶体变形引起预张力的损失;本文基于试验结果给出锚固胶体变形与应力差值的回归公式,可用于评估SC-BRB震后的预张力损失;摩擦保险装置在保证较大摩擦面积和避免摩擦面锈蚀的前提下,滑动摩擦力受加载制度变化的影响很小,性能十分稳定。 (3) 新型预拉杆式SC-BRB支撑试件的拟静力试验。设计并加工了4根分别采用不同改进措施的新型预拉杆式SC-BRB试件,结果表明:未采用增大支撑变形能力措施的SC-BRB试件在预拉杆超过应变极限断裂后,支撑的承载力出现陡降,残余变形增大到位移幅值的90%;摩擦保险装置能保证SC-BRB试件达到对应4%层间位移角的轴向变形而不出现破坏,并使支撑具有一定的自定心能力;当支撑轴向变形相同时,串联式SC-BRB的构造形式既能减小预拉杆弹性延伸率一半需求,也不会影响支撑的自定心性能;采用橡胶夹层端板能够有效降低套管长度误差的影响,提高支撑初始刚度的可控性。 (4) 新型预拉杆式SC-BRB支撑滞回性能的数值模拟。采用ABAQUS有限元分析软件建立新型预拉杆式SC-BRB的精细有限元模型,通过与试验结果的对比验证了模型的正确性,并在此基础上分析了关键参数对支撑滞回性能的影响。基于流变分析理论,建立能够模拟受橡胶夹层端板和套管长度误差影响的不同预拉杆材料SC-BRB滞回性能的弹塑性分析模型。 (5) SC-BRB框架抗震性的参数化分析。基于结构的恢复力模型和运动方程,分别确定影响SC-BRB铰接钢框架(即梁、柱铰接的SC-BRB框架)和SC-BRB双重体系框架(即由抗弯框架和SC-BRB铰接钢框架组成的SC-BRB框架)动力响应的关键参数。采用OpenSees软件建立两种形式SC-BRB框架的简化杆系模型,通过时程分析研究关键参数对结构抗震性能的影响规律,并给出结构设计时各参数的取值建议。 (6) SC-BRB框架的非线性位移比谱和残余位移比谱公式的建立。基于SC-BRB框架单自由度体系模型,研究关键参数对其非线性位移比和残余位移比的影响规律。分别对SC-BRB铰接钢框架和SC-BRB双重体系框架进行162000次和486000次单自由度体系时程分析,在此基础上通过多元非线性回归,建立分别适用于SC-BRB铰接钢框架和SC-BRB双重体系框架的非线性位移比和残余位移比公式,可用于结构地震时的位移评估和抗震设计。 (7) 以最大层间位移角和残余位移角为双控指标,建立SC-BRB框架基于震后可修复性的抗震设计方法。研究了高阶模态效应和P-Δ效应对不同层数SC-BRB框架地震位移响应的影响,分别给出结构最大变形和残余变形的高阶模态放大系数回归公式,以及P-Δ效应放大系数参考值。采用最大层间位移角和残余位移角作为双控指标,在非线性位移比与残余位移比公式的基础上,建立适用于SC-BRB框架的基于震后可修复性的抗震设计方法,并分别给出SC-BRB铰接钢框架和SC-BRB双重体系框架的设计流程。
英文题目 Seismic Performance and Design Method of an Innovative Self-Centering BRB Frame with Pre-Tensioned Tendons
英文主题词 Self-centering buckling restrained brace, seismic performance, nonlinear drift ratio, residual drift ratio, seismic design method
英文摘要 Self-centering buckling-restrained brace (SC-BRB) has both a good energy dissipation capability and self-centering effect, which can effectively improve the reparability of the structure after a strong earthquake. However, for the preexisting SC-BRB, the pre-tensioned tendons may yield to fracture, which would affect the safety and reparability of the structure during strong earthquake events. In addition, SC-BRB frames may exhibit a certain residual deformation when pre-tensioned tendons can not meet the structural deformation demand and the adjacent resisting-moment frame yields. At present, the design of SC-BRB frames adopts the displacement-based seismic design method that aims to control the peak story drift, rather than the residual drift. This method can not ensure the reparability of the structure after earthquakes. For the above problems, this paper has made the following works. (1) Concept and configuration of an innovative SC-BRB with pre-tensioned tendons, which can increase deformation capacity and initial stiffness of braces, have been proposed. Due to the constructional limitation of the preexisting SC-BRB, a high elastic elongation of the pre-tensioned tendon was demanded, which would result in a low deformation capability of SC-BRB. Besides, the issue that the tube length error would cause the practical initial stiffness of SC-BRB smaller than the theoretical value, was worth addressing. This paper had provided some measures to deal with these issues, such as the friction fuse or series SC-BRB for enhancing the deformation capability, and the rubber sandwich end plate for strengthening the initial stiffness controllability. Thus, an innovative SC-BRB with pre-tensioned tendons was proposed. After deeply analyzing the working mechanism and mechanical behavior, the design method and procedure for the proposed SC-BRB were developed. (2) Experimental investigations on the pre-tensioned tendons and the friction fuse. The experimental investigation of pre-tensioned tendons made by basalt fiber-reinforced polymer (referred as BFRP) and friction fuse devices were conducted. The experimental results showed that the ultimate elongation of BFRP rebar exceeded 2.5% and this material exhibited a stable performance. However the epoxy deformation in the anchorage would lead to a relative displacement between the BFRP rebar and the anchorage device during the cycle tension of pre-tensioned tendons. Based on the experimental results, this paper provided the regression formula describing the relationship between the epoxy deformation and the stress difference, which could be used to evaluate the loss of pre-stressed force in SC-BRB after earthquakes. Supposing that the friction fuse was equipped with a large friction area and no rustiness in the surface, the loading rate or displacement amplitudes would almost have no influence on the sliding friction force. Moreover, the sliding friction force showed an unobvious variation and exhibited a stable performance after several cyclic loadings. (3) Quasi-static tests of SC-BRB specimens. Four SC-BRB specimens with different improvement measures were designed and manufactured. The test results showed that for SC-BRB without improving the deformation capability, the bearing force would drop steeply and the residual deformation would increase to 90% of the displacement amplitude when the pre-tensioned tendons fractured due to exceeding the strain limit. The friction fuse could protect SC-BRB specimens from being damaged when the specimens experienced an axial deformation corresponding to the 4% inter-story drift. And the SC-BRB specimens possessed a certain self-centering ability. When the axial deformation of the brace is the same, the configuration of the series SC-BRB would meet the demands to reduce half of the pre-tensioned tendon’s elastic elongation. At the same time, the self-centering capacity would not be affected. The use of the rubber sandwich end plate could effectively reduce the influence of the tube length errors and improve the controllability of the initial stiffness of SC-BRB. (4) Numerical simulations of the hysteretic behavior of SC-BRB. Based on the ABAQUS finite element analysis software, the fine analytical model of SC-BRB was established and the accuracy was verified by comparing numerical and experimental results. The influences of several key parameters on the hysteretic behavior of SC-BRB were investigated. In addition, based on the rheological analysis theory, this paper established an elastic-plastic analysis model to consider the influences of both the rubber sandwich end plate and the tube length errors on the hysteretic performance of SC-BRB with different pre-tensioned tendon materials. (5) Parametric analysis on the seismic performance of SC-BRB frames. The key parameters that influence the seismic response of SC-BRB hinged steel frame and SC-BRB dual system frame were determined based on the structural hysteretic model and the dynamic equation. The two simplified model of SC-BRB frames were established via the OpenSees software. The influence of key parameters on the seismic performance of structures was conducted by time history analyses and the parameter values in structural design were suggested. (6) Establishment of the nonlinear drift ratio spectrum and the residual drift ratio spectrum of SC-BRB frames. Based on the single degree-of-freedom model of SC-BRB frames, the influences of key parameters on both the nonlinear drift ratio and the residual drift ratio were investigated. 162000 and 486000 time history analysis for the single freedom system of SC-BRB hinged steel frame and SC-BRB dual system frame were conducted. The numerous regression analysis on the time history analysis results of the single-degree-freedom system, the nonlinear drift ratio formula, as well as the residual drift ratio formula, were established respectively for SC-BRB hinged steel frames and SC-BRB dual system frames. In addition, the displacement evaluation and structure seismic design were conducted. (7) A seismic design method based on the post-earthquake reparability of the structure which considers both the peak story drift and the residual drift as the controllable index. The influences of high modal and P-Δ effect on the seismic displacement response of SC-BRB frames with different floors were studied. The regression formulas of the high modal amplification factor of the peak story drift and residual drift, which could be applicable for SC-BRB frames and SC-BRB dual system frames, were given respectively, as well as the referenced amplification factor of the P-Δ effect. Finally, selecting the peak story drift and residual drift as the controllable index and according to the formula of nonlinear displacement ratio and residual displacement ratio, this paper established a seismic design method based on the post-earthquake reparability of the structure, and this method was applicable for SC-BRB frame. The design procedure of SC-BRB steel frames and SC-BRB dual system frames were given.
学术讨论
主办单位时间地点报告人报告主题
东南大学党委研工部 2014年10月14日 群贤楼三楼报告厅 谢礼立院士 培养研究生的几个关键问题
东南大学土木工程学院 2015年1月15日 逸夫科技馆报告厅 聂建国院士 中国工程院聂建国院士受聘东南大学兼职教授仪式暨学术报告会
东南大学土木工程学院 2015年5月11日 榴园宾馆新华厅 杨永斌院士 希望之匙在我手中
东南大学党委研工部 2015年4月29日 逸夫建筑馆15楼大会议室 斋藤公男教授 日本大学斋藤公男教授学术报告会
东南大学土木工程学院 2014年5月14日 逸夫建筑馆707会议室 谢钦 SC-BRB框架流变模型
东南大学土木工程学院 2015年9月11日 逸夫建筑馆707会议室 谢钦 SC-BRB框架抗震性能参数化分析
东南大学土木工程学院 2015年12月5日 逸夫建筑馆707会议室 谢钦 基于性能的设计方法概述
东南大学土木工程学院 2016年4月12日 逸夫建筑馆707会议室 谢钦 期刊论文写作与投稿
     
学术会议
会议名称时间地点本人报告本人报告题目
8th International Symposium on Steel Structures 2015年11月5日-7日 韩国济州岛 The influence of several design parameters on the seismic response of multi-storey buildings with self-centering energy dissipative braces
1th China-Canada symposium on Structural and Earthquake Engineering 2017年8月20日-24日 加拿大温哥华不列颠哥伦比亚大学 New technics to improve the performance of self-centering buckling-restrained braces
     
代表作
论文名称
Influence of tube length tolerance on seismic responses of multi-storey buildings with dual-tube sel
Parametric analysis and direct displacement-based design method of self-centering energy dissipative
SMA预拉杆式自定心屈曲约束支撑的滞回性能分析
两种设计原则下自定心屈曲约束支撑框架的抗震性能分析
自定心摩擦耗能支撑的套筒长度误差对多高层结构地震响应的影响
Finite element analysis of dual-tube self-centering buckling-restrained braces with composite tendon
 
答辩委员会组成信息
姓名职称导师类别工作单位是否主席备注
冯健 正高 教授 博导 东南大学
范进 正高 教授 硕导 南京理工大学
俞伟根 正高 研究员级高工 其他 江苏省建筑科学研究院有限公司
范圣刚 正高 教授 博导 东南大学
汪昕 正高 教授 博导 东南大学
      
答辩秘书信息
姓名职称工作单位备注
冯德成 其他 讲师 东南大学