新型纯钢屈曲约束支撑耗能性能研究

发布时间：2018-05-06 19:31

本文选题：屈曲约束支撑 + 纯钢　；参考：《中国地震局工程力学研究所》2017年硕士论文

【摘要】：屈曲约束支撑轴向受压或受拉均能达到屈服而不发生屈曲,与传统普通支撑相比,其良好的滞回耗能性能及稳定的力学性能越来越受到工程师的追捧,且其施工安装方便、经济、设计灵活、不影响主体结构美观等优点,使得屈曲约束支撑不仅是新建建筑物抗震设计的首要选择之一,也是已建成建筑物抗震加固和改造的重要手段。本文采用Q235B与工业纯铁作为内芯板材研发了一种经济型较好的新型纯钢屈曲约束支撑,结合拟静力试验和有限元数值模拟对其耗能性能进行了初步研究。主要研究内容如下:首先,依据现有理论和参考文献,对新型屈曲约束支撑整体稳定性、内芯局部屈曲稳定性、外部约束单元局部稳定性及局部抗弯承载力、连接段扭转承载力进行设计和验算。针对支撑细部构造,从力学和几何两方面进行设计。其次,运用ABAQUS软件对新型屈曲约束支撑进行有限元建模,对支撑耗能产生影响的参数:内芯初始弯曲缺陷,内芯与外部约束单元之间摩擦系数,内芯与外部约束单元之间间隙,内芯宽厚比,约束比,外部约束单元厚度等进行分析,验证现有理论的可靠性与准确性。然后,依据新型屈曲约束支撑试件的拟静力试验结果,研究了屈曲约束支撑在不同内芯板材,不同外部角钢,不同内芯宽厚比下的滞回耗能性能。试验结果表明,采用工业纯铁作为内芯板材系列的试件较之以Q235B为内芯板材的试件,其滞回曲线相对饱满但不稳定,疲劳性能较好,延性较好。采用两种不同尺寸的角钢作为外部约束单元的试件,在相同条件下,试件的相关的力学参数及耗能性能评价指标基本一致。内芯宽厚比取值为8的试件较之内芯宽厚比取值为10的试件,其滞回曲线相对饱满,内芯最大应力值较小,内芯局部稳定性较好。最后,对新型纯钢屈曲约束支撑基于ABAQUS有限元模拟,有限元模拟结果与试验结果在相关的力学参数及耗能评价指标上基本一致,滞回曲线基本吻合。由于采购的工业纯铁钢材,力学性能不够稳定,以材性试验结果作为工业纯铁的本构参数,其模拟结果与试验结果在支撑屈服力等稍有差别。
[Abstract]:Buckling restrained braces can reach yield under axial compression or tension without buckling. Compared with conventional braces, their good hysteretic energy dissipation performance and stable mechanical properties are more and more popular by engineers, and their construction and installation are convenient. Because of the advantages of economy, flexible design and no influence on the beauty of the main structure, buckling restrained bracing is not only one of the first choices in the seismic design of newly built buildings, but also an important means of seismic reinforcement and reconstruction of completed buildings. In this paper, Q235B and industrial pure iron are used as inner core plates to develop a new kind of economical pure steel buckling restraint braces. The energy dissipation performance of Q235B and industrial pure iron is studied with pseudo-static test and finite element numerical simulation. The main research contents are as follows: firstly, according to the existing theories and references, the global stability, the local buckling stability of the inner core, the local stability of the external restraint element and the local bending bearing capacity of the new buckling restrained braces are studied. The torsional bearing capacity of connection section is designed and checked. Aiming at the structure of the supporting detail, the design is carried out from the two aspects of mechanics and geometry. Secondly, the finite element model of the new buckling restrained braces is established by using ABAQUS software. The parameters that affect the energy consumption of the braces are the initial bending defects of the inner core, the friction coefficient between the inner core and the external constraint element, the gap between the inner core and the external constraint element, and the gap between the inner core and the external constraint element. The width to thickness ratio of inner core, constraint ratio and thickness of external constraint unit are analyzed to verify the reliability and accuracy of existing theories. Then, according to the quasi-static test results of the new buckle-constrained bracing specimens, the hysteretic energy dissipation performance of buckle-constrained braces under different core plates, different external angle steels and different ratio of width to thickness of the inner core is studied. The results show that the hysteretic curve of industrial pure iron is relatively full but unstable, the fatigue property is better and the ductility is better than that of Q235B. Two kinds of angle steel with different sizes are used as external restraint elements. Under the same conditions, the mechanical parameters and energy dissipation performance of the specimens are basically the same. When the ratio of width to thickness of inner core is 8, the hysteresis curve is relatively full, the maximum stress of inner core is smaller, and the local stability of inner core is better than that of the specimen with ratio of width to thickness of inner core. Finally, the buckling restrained braces of new pure steel are simulated by ABAQUS finite element method. The results of finite element simulation are basically consistent with the experimental results in terms of related mechanical parameters and energy dissipation evaluation indexes, and the hysteretic curves are in good agreement with each other. Because the mechanical properties of the industrial pure iron steel purchased are not stable, the material test results are taken as the constitutive parameters of the industrial pure iron, and the simulation results are slightly different from the test results in the support yield force and so on.
【学位授予单位】：中国地震局工程力学研究所
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU352.1

【参考文献】