摩擦滑移隔震框架结构试验与设计方法研究

发布时间：2018-09-17 20:36

【摘要】：摩擦滑移隔震是结构隔震的主要型式之一,其隔震效果取决于滑移隔震支座的性能,而摩擦系数是影响支座性能的主要因素。一般来说,摩擦系数越小,隔震效果就会越好,但过小的摩擦系数却会造成滑移位移过大,增加限位复位的难度,甚至影响建筑物的使用功能。二硫化钼具有良好的附着性、耐高温抗高压性以及低摩擦性等优点,被誉为“高级固体润滑油王”。文中采用二硫化钼固体润滑剂作为隔震支座的摩擦材料,并以软钢实体圆锥棒作为限位消能器,设计制作了一种新型滑移隔震装置。将其应用到一五层钢筋混凝土框架结构中,进行了Simulink仿真分析和振动台试验研究,并探讨了摩擦滑移隔震结构的设计方法。主要工作和研究内容如下:(1)分析了新型滑移隔震支座的设计要点和工作原理,介绍了二硫化钼材料的性能和优点,采用MTS电液伺服试验系统,对其进行了不同竖向荷载下的摩擦性能试验,探讨了二硫化钼作为新型隔震系统滑移材料的可行性,并通过函数拟合建立了摩擦系数与竖向压应力的函数关系式。结果表明,隔震支座的摩擦恢复力曲线符合库伦摩擦力模型,二硫化钼涂层材料摩擦性能稳定,摩擦系数约为0.04~0.05,可以作为建筑滑移隔震系统的滑移材料。(2)基于量纲理论,在综合考虑振动台承载能力的基础上,按照一致相似关系设计了一个比例为1:5五层钢筋混凝土框架结构试验模型,并对其进行了模拟地震振动台试验。结果表明:摩擦滑移隔震技术延长了结构体系的自振周期;相比10Hz谐波,2Hz谐波时隔震层产生的滑移量明显变大,隔震层位移对频谱特性较为敏感。纯滑移和限位滑移时隔震结构的层间位移都很小,加速度呈“K”字形分布,达到了理想的减震效果;三维地震作用下的隔震层滑移量相比X单向滑移时略有增大,其X向的加速度反应处于X向抗震和X向滑移之间,最大减震效果为51.46%,表明了竖向地震作用下摩擦滑移隔震技术依然有效;采取水箱滑移隔震技术后,水箱的加速度响应出现了明显地衰减,屋面凸出物的鞭梢效应得到了较好地抑制,且主体结构的地震反应也有一定的减小,表明附加层滑移隔震措施,可以作为抗震设计时结构体系的第二道抗震防线。(3)以五层框架试验模型的原型为计算模型,综合运用Matlab编程语言、GCI工具和Simulink仿真模块,其中库伦摩擦力采用Stateflow有限状态机来模拟,弹塑性圆锥棒限位器的滞回特性采用Bouc-Wen模型来描述,以此建立了滑移隔震结构的Simulink主仿真模型,包括上部结构仿真模型、隔震层仿真模型、能量反应仿真模型、限位器仿真模型和摩擦力子模型。分析了不同地震波下结构体系的动力反应和能量反应规律。结果表明,强震记录时抗震结构的仿真与试验加速度值吻合的较好,滑移结构的隔震层滑移量比较接近,误差较小。随着摩擦系数的增大,结构地震总输入能总体上呈上升趋势,且当摩擦系数增大到0.15时,结构总输入能变化已不再明显。随着预留滑移量的增大,地震总输入能逐渐减小,隔震性能逐渐提高,但隔震层的总滞回耗能也逐渐减小,其滞回耗能比变化不大,在0.86左右,相比抗震结构,不同滑移量下的隔震层都能较好地发挥滞回耗能,且减震效果相当;隔震层的最大滑移量随预留滑移量的增加而增大,滞回曲线饱满,限位器起到了良好的限位消能作用,摩擦滑移隔震结构获得了较好的减震效果。(4)根据国内外相关设计标准和规范规程以及前人的理论分析和试验研究成果,并结合多年试点工程总结的宝贵经验,总结和探讨了现阶段适合于滑移隔震结构的设计方法,包括初步设计、隔震层的设计、限位消能装置的设计以及上部结构、下部结构和地基基础的设计构造方法等,为后人进行滑移隔震结构设计提供了一定的参考依据,有助于滑移隔震结构在实际工程中的推广使用。最后运用SAP2000有限元软件对一多层框架结构工程实例进行了滑移隔震设计,分析了其减震效果。
[Abstract]:Friction-sliding isolation is one of the main types of structural isolation. Its isolation effect depends on the performance of sliding isolation bearings, and friction coefficient is the main factor affecting the performance of bearings. Molybdenum disulfide is known as "king of advanced solid lubricants" because of its good adhesion, high temperature resistance, high pressure resistance and low friction. A new type of sliding isolation device is introduced. Simulink simulation analysis and shaking table test are carried out in a five-story reinforced concrete frame structure. The design method of friction sliding isolation structure is discussed. The main work and research contents are as follows: (1) The design points and working principle of the new type of sliding isolation bearing are analyzed. The properties and advantages of molybdenum disulfide are introduced. The friction properties of molybdenum disulfide under different vertical loads are tested by MTS electro-hydraulic servo test system. The feasibility of molybdenum disulfide as a new sliding material for vibration isolation system is discussed. The functional relationship between friction coefficient and vertical compressive stress is established by function fitting. The friction restoring force curve of isolation bearings accords with Coulomb friction model. The friction performance of molybdenum disulfide coating material is stable, and the friction coefficient is about 0.04~0.05. It can be used as sliding material of building sliding isolation system. (2) Based on dimension theory, considering the bearing capacity of shaking table, a uniform similarity relation is designed. The results show that the frictional sliding isolation technique prolongs the natural vibration period of the structure system, and the sliding quantity of the isolation layer increases obviously when compared with the 10Hz harmonic wave, and the displacement of the isolation layer is more sensitive to the spectrum characteristics. The displacement between layers of isolation structure is very small, and the acceleration distribution is "K" shape, which achieves the ideal damping effect; the slip of isolation layer under three-dimensional earthquake is slightly larger than that under X-direction slip, and the acceleration response in X-direction is between X-direction seismic resistance and X-direction slip, the maximum damping effect is 51.46%, indicating that the vertical seismic isolation layer slip is slightly larger than that under X-direction slip. Friction sliding isolation technology is still effective under earthquake action; after adopting water tank sliding isolation technology, the acceleration response of water tank appears obvious attenuation, the whiplash effect of roof protrusion is well suppressed, and the seismic response of main structure is also reduced to a certain extent, indicating that the additional layer sliding isolation measures can be used as seismic design. (3) Based on the prototype of the five-story frame test model, the MATLAB programming language, GCI tools and Simulink simulation module are used to simulate the Coulomb friction. The Stateflow finite state machine is used to simulate the Coulomb friction, and the Bouc-Wen model is used to describe the hysteretic characteristics of the elastic-plastic cone bar limiter. Simulink main simulation model of sliding isolation structure is established, including superstructure simulation model, isolation layer simulation model, energy response simulation model, limit simulation model and friction sub-model. With the increase of friction coefficient, the total seismic input energy of the structure shows an upward trend, and when the friction coefficient increases to 0.15, the change of the total input energy of the structure is no longer obvious. The energy input decreases gradually and the isolation performance improves gradually, but the total hysteretic energy dissipation of the isolation layer decreases gradually. The hysteretic energy dissipation ratio of the isolation layer has little change at about 0.86. Compared with the aseismic structure, the isolation layer with different slip can play a better role in hysteretic energy dissipation, and the maximum slip of the isolation layer increases with the reserved slip. With the increase of hysteresis curves and the saturation of hysteresis curves, the restrictor plays a good role in limiting energy dissipation, and the friction-sliding isolation structure achieves a better damping effect. (4) Based on the relevant design standards and codes at home and abroad, as well as the theoretical analysis and experimental research results of predecessors, and combined with the valuable experience of many years of pilot projects, this paper summarizes and discusses the present situation. The design method of sliding isolation structure, including preliminary design, isolation layer design, limit energy dissipation device design, upper structure, lower structure and foundation design and construction method, is suitable for sliding isolation structure design. Finally, the sliding isolation design of a multi-story frame structure is carried out by using the finite element software SAP2000, and the damping effect is analyzed.
【学位授予单位】：西安建筑科技大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TU352.12

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