纤维橡胶支座的力学性能研究

针对目前的铅芯橡胶支座(LRB)存在的大体积、笨重、施工安装不便且生产工艺复杂等缺点,采用纤维布代替内部钢板,开发新型的隔震支座——纤维橡胶支座(FREI)。采用ABAQUS对纤维橡胶支座进行了静力和动力有限元分析,分析了纤维橡胶支座在竖向荷载和剪切荷载作用下纤维布和橡胶的应力分布规律,并讨论了纤维橡胶支座的破坏特征。比较了纤维橡胶支座和铅芯橡胶支座的力学性能,结果表明,纤维橡胶支座拥有与铅芯橡胶支座相当的竖向压缩性能和水平剪切性能,可为纤维橡胶支座的进一步研究及实际应用提供参考。     

铅芯橡胶隔震支座水平刚度影响因素数值分析

通过有限元分析软件ANSYS对铅芯橡胶隔震支座力学性能分析,研究了铅芯橡胶隔震支座水平等效刚度(水平刚度)的主要影响因素.采用四分之一的铅芯橡胶支座模型进行模拟分析,大大缩短了有限元软件运行的时间,并获得较好的结果.在此基础上,总结了水平剪应变,以及在不同剪应变下竖向压应力、第二形状系数、橡胶剪切模量和铅芯直径对水平刚度的影响.分析结果表明,水平刚度随水平位移的增加而减小,随第二形状系数、橡胶剪切模量和铅芯直径的增加而增加;而竖向压应力则对水平刚度几乎无影响;并且当水平剪应变较小时,水平刚度受其影响因素的影响较大,即当隔震结构遭受小震时,隔震层的水平刚度受地震作用的影响较大.     

不同尺寸铅芯橡胶隔震支座力学性能的有限元分析

研究不同尺寸铅芯橡胶隔震支座力学性能的变化规律,为小比例隔震结构模型隔震层的相似设计提供依据。采用ABAQUS对不同尺寸的铅芯橡胶隔震支座进行有限元分析。在橡胶和薄钢板厚度按比例变化的情况下,分析了不同尺寸铅芯橡胶隔震支座在竖向荷载和剪切荷载作用下的力学性能,研究了竖向刚度、水平等效刚度、屈服后刚度、屈服剪力、等效阻尼比等随铅芯橡胶隔震支座尺寸的变化规律.分析结果表明:竖向刚度、水平等效刚度、屈服后刚度等随铅芯橡胶支座尺寸的增大而线性增大,等效阻尼比与铅芯橡胶支座的尺寸关系不大,支座屈服剪力与铅芯直径尺寸近似成二次抛物线变化的关系。     

铅芯橡胶支座参数对隔震储罐地震响应的影响

利用Bouc-Wen模型模拟铅芯橡胶支座的力-变形非线性行为,研究了两种高径比铅芯橡胶支座(LRB)隔震储罐的地震动力响应特征,系统探讨铅芯橡胶支座动力参数对隔震储罐地震反应的影响规律.研究表明:基底设置铅芯橡胶支座后,储罐有良好的减震效果,减震效果评价指标基底剪力、支座位移、晃动波高都得到有效控制.隔震频率是影响LRB隔震储罐减震性能的主要参数,屈服强度参数、支座阻尼比影响次之.增大支座屈服强度可增加有效隔震频率范围,降低支座位移,但不一定能起到降低波高作用.高隔震频率、无阻尼比工况时,储罐地震响应远超过未隔震时响应;增大阻尼比可同时降低支座位移和晃动波高.在高隔震频率下,存在最优屈服强度和阻尼比,使得基底剪力最小.为使隔震支座发挥最大减震作用,应根据储罐不同高径比特点来优化配置铅芯橡胶支座参数.     

柔性直流换流阀LRB隔震性能分析

以一柔性直换流阀为研究对象，进行了铅芯橡胶隔震支座(LRB)基础隔震设计，通过ANSYS有限元模拟得到隔震前后结构的动力响应，对比分析了LRB隔震性能，结果显示：该柔性直流换流阀LRB隔震方案隔震性能优异，可显著降低震中换流阀结构应力和加速度响应，提高柔性直流换流阀结构的安全性。     

铅芯橡胶支座隔震储罐地震响应特性分析

利用双线性恢复力模型模拟铅芯橡胶支座力学特性,探讨了不同类型场地上,隔震储罐在铅芯橡胶支座(LRB)与叠层橡胶支座(RB)两种隔震方式下的地震响应特点.研究表明:铅芯屈服力、场地类型和地震强度是影响LRB减震性能的主要因素.与RB隔震方式相比,LRB具有降低基底剪力、支座位移、晃动波高等优点,但减震效果并不总是好于RB方式,与场地类型和铅芯屈服力的选取有关.特别是Ⅳ类场地上RB支座更适合储罐隔震设计.支座最优屈服力参数选取需要根据储罐自振特点、场地类型和地震强度共同确定.LRB支座更适合在高烈度地区应用,减震效率高而且稳定.     

组合式三维隔震支座力学性能试验研究

提出并设计了一种新型组合式三维隔震支座(3DIB),该支座由铅芯橡胶支座(LRB)和组合式碟形弹簧竖向隔震支座(DSB)组合而成,并进行了性能试验。性能试验结果表明,3DIB具有与LRB类似的水平特性、与DSB近似的竖向特性。3DIB具有可变的水平刚度与竖向刚度,水平等效阻尼比与竖向等效阻尼比均达到20%左右,并且具有较高的承载力,可以用于建筑结构的三维隔震。     

阜阳市城南新区综合建设PPP项目(图书馆、博物馆与市民广场)

<正>质量技术特点博物馆为带隔震支座的框架结构,地下室与地上结构之间设置隔震层,层高1.8m,以隔震技术为特点。(1)隔震支座采用G4普通橡胶支座(LNR)和铅芯橡胶支座(LRB),有效直径分别为590、690、790、890、990(mm),共156个支座;(2)混凝土斜墙隔震缝,缝隙为30mm聚苯板填充,且墙与结构设计为非刚性连接;(3)楼梯在转换层处设置5mm聚四     

小尺寸铅芯橡胶支座力学性能试验研究

小尺寸铅芯橡胶支座因其优越的性能被广泛应用于设备设施隔震(振)需求,也常用于隔震结构缩尺模型试验中。定量把控小尺寸铅芯橡胶支座的力学性能是准确、定量评估隔震(振)结构动力响应的重要保证。然而,由于小尺寸铅芯橡胶支座的尺寸、形状系数等参数超出现行规范限制,其力学性能特性与普通铅芯橡胶支座有所不同,值得深入开展研究。本文设计并制作了4组小尺寸铅芯橡胶支座试件,通过试验研究不同形状系数试件在不同竖向压应力下的力学性能,评估现有理论计算公式适用性,并基于试验提出小尺寸铅芯橡胶支座力学性能的修正公式。研究成果可为定量分析小尺寸铅芯橡胶支座的力学性能,实现支座的精细化设计制作提供参考。     

实时往复大变形下铅芯橡胶隔震支座力学性能试验研究

针对铅芯橡胶隔震支座在大变形多次实时往复荷载下力学性能退化问题,采用足尺铅芯橡胶隔震支座,通过高速压剪试验设备,对铅芯橡胶隔震支座进行了基本竖向力学性能试验、基本水平力学性能试验、多次不同大变形下实时加载水平力学性能试验,试验结果显示：铅芯橡胶隔震支座在实时往复多次大变形下,随着加载圈数的增加,隔震支座屈服力急剧下降,支座耗能能力降低,到试验结束时屈服力平均下降46.1%,加载圈数对屈服后刚度影响相对较小;实时往复大变形下测得的铅芯橡胶隔震支座屈服力在第2圈以后均小于采用国家标准试验方法得到的屈服力,试验结束时屈服力小于国家标准测到屈服力的43.8%,国家标准试验方法测得的屈服力与实际地震下铅芯橡胶隔震支座的屈服力相比偏小;铅芯橡胶隔震支座实时多次往复变形对其竖向刚度基本没有影响;铅芯橡胶隔震支座在实时往复大变形试验时其力学性能退化,静置一段时间后,其性能基本又恢复到实时往复大变形试验前的状态。     

Rubber effect on metallic dampers used on the supports of steel cross members

There are many strengthening methods made with steel cross members for strengthening the structures with inadequate earthquake behavior. This type of strengthening methods is also effective in buckling of the cross members in the behavior of the structural frames. This buckling may cause partial or complete collapse of the structure. Thus, it is quite important to prevent and limit the formation of buckling in steel crosses. At the TEC 2018, the insulation unit is defined as the elements that can exhibit flexible behavior on the horizontal direction and rigid behavior on the vertical direction under the effect of earthquake loads. The basic principle of using insulation units is that these members can dissipate energy in the carrier system. The originality of this study is to experimentally investigate the damper behavior created by using cylindrical rubber wedges, which can be easily found in the automotive industry, in combination with steel plates and bolts. In this experimental study, the contribution of seismic insulators to the structural element to be strengthened was investigated. The insulators used in this study are considered by analogy with lead-core rubber insulators. As such seismic lead-core rubber insulators move under the influence of lateral loads, the lead core inside makes plastic deformation, thus increasing the damping rate. In this insulator study, it is aimed to use U plates or bolts instead of lead core. While vertical loads are covered by rubber support, horizontal loads will be damped due to plastic deformation of U plates or bolts. The five types of seismic dampers were used as 10 B-type rubber wedge mounted damper (SR), 2 U-type steel plates damper (SP), 10 M6 steel bolted damper (SB), 2 U-type steel plates and 10 B-type rubber wedge mounted damper (SPR), 10 M6 steel bolted, and 10 C-type rubber wedge mounted damper (SBR). These specimens were tested under lateral loading and constant vertical loading. The results obtained at the end of the tests shall be compared considering the strength, stiffness, and dissipated energy capacities of the specimens.     

椭圆形钢管混凝土构件纯弯力学性能分析

利用有限元软件ABAQUS建立椭圆形钢管混凝土构件纯弯力学性能分析的有限元计算模型,并通过6个椭圆形钢管混凝土构件纯弯试验验证有限元计算模型的准确性。在此基础上对其受力全过程中钢管及混凝土应力分布情况进行分析,同时给出钢管与核心混凝土之间的相互作用,并对剪跨比、钢管强度、混凝土强度、短轴长和长轴长等参数对纯弯时构件极限承载力及荷载-位移曲线的影响进行比较。结果表明:椭圆形钢管混凝土构件在跨中发生倾向弯曲破坏,钢管屈服强度、混凝土强度、长轴长、短轴长及钢管壁厚等参数对其力学性能影响显著,剪跨比对其力学性能影响不明显。     

基于ANSYS的LRB性能模拟验证分析

铅芯橡胶支座(LRB)是一种有效的隔震装置,它通过延长结构的周期、增加结构的阻尼来减小结构的地震反应.在结构隔震分析中,LRB扮演了一个很重要的角色,对其模拟程度的正确与否对整个结构的分析结果将产生很大影响.本文采用大型通用有限元程序ANSYS,对一个单自由度隔震体系进行了LRB性能模拟验证分析,分析表明:在合理确定输入地震动PGA临界点的前提下,采用ANSYS中的Combin40单元来模拟LRB的滞回性能,能获得较为满意的效果;同时通过与SAP2K时程分析比较,也验证了ANSYS分析结构隔震的可靠性.     

Flexural performance of rectangular CFST members

This paper presents a finite element analysis (FEA) modeling to study the flexural performance of rectangular concrete filled steel tubular (CFST) members with compact, non-compact or slender element sections. Seventy test results are used to verify the FEA modeling. Generally good agreements were achieved in the ultimate bending capacity and the curvilinear trends of the moment versus mid-span deflection relations of the composite member between the experimental results and the FEA results. The FEA modeling is then used to investigate the residual failure patterns of the core concrete, the typical residual deformations of outer steel tube and the stress and strain distributions across the composite section in the whole loading procedure. Analysis results show that interaction of steel and concrete in the composite beam offers stress redistribution in steel and concrete which makes the rectangular CFST beam have high flexural capacity and ductility. Finally, the reliability analysis method is used to calibrate the existing design formulae on composite beam in EC4 (2004), AISC (2010) and DBJ/T13-51-2010 (2010). It was found that all the design formulae achieved adequate reliability index.     

钢管再生混凝土构件受力机理研究

在确定钢管与核心再生混凝土本构关系模型的基础上,采用有限元法对钢管再生混凝土轴压短柱、纯弯构件和压弯构件的破坏模态和荷载-变形关系曲线进行全过程分析,揭示出受力过程中钢管与核心再生混凝土截面应力分布规律及钢管与核心再生混凝土之间的相互作用,较为深入地认识了静力荷载作用下钢管再生混凝土构件的工作机理。     

铅芯橡胶阻尼器性能研究

通过不同位移幅值、不同频率和不同循环的加载试验，研究了铅芯橡胶阻尼器的工作性能。根据试验所得各个工况的滞回曲线，计算了铅芯橡胶阻尼器的等效刚度和等效粘滞阻尼比，并提出了其等效刚度的计算公式。研究表明，铅芯橡胶阻尼器的等效刚度和等效粘滞阻尼比受加载频率影响不明显；且阻尼器在经历疲劳荷载后，其等效刚度略有下降，等效粘滞阻尼比维持不变，说明铅芯橡胶阻尼器的工作性能稳定，能够应用于结构的消能减震设计。     

初始荷载下中空钢管混凝土柱轴向强度

与传统的钢管混凝土柱相比,中空钢管混凝土(CFDST)柱具有很多优点,诸如自重轻和良好的循环性能。CFDST柱可能被用于桥梁,高层建筑,高架桥和输电塔结构中。内外钢管将承担来自上部结构和浇筑的湿混凝土的初始荷载。由这些初始荷载造成的钢管初应力和变形会影响CFDST构件的性能。因此,对外钢管单独承担初始荷载和内外钢管同时承担初始荷载时,CFDST柱的轴力性能进行讨论。建立通用的有限元模型预测钢管负荷时CFDST柱的性能。通过承担初始荷载和不承担初始荷载的CFDST柱的试验结果对该有限元模型进行验证。讨论初始荷载水平、长细比、空心率和材料强度对轴向强度的影响。最后,给出初始荷载下的CFDST柱的极限强度计算公式。     

锥形中空钢管混凝土(CFDST)短柱的性能

目前,虽然锥形中空钢管混凝土(CFDST)柱被用于中国的输电塔中,但是关于这类输电塔中构件性能的信息仍很缺乏。因此,本文对锥形CFDST短柱的轴压性能进行研究。研究的参数包括锥角和截面尺寸。通过建立有限元模型分析锥形构件的性能。结果表明,钢管和夹层混凝土不受锥角影响,能够很好地协同工作。锥形CFDST短柱的失效模式与直线型的类似,失效出现在最小截面附近。通过应力分析讨论锥形构件的约束效应。最后,给出用于计算锥形CFDST短柱极限强度的建议公式。     

Behaviour of tapered concrete-filled double skin steel tubular (CFDST) stub columns

Recently, tapered concrete-filled double skin steel tubular (CFDST) columns have been applied in electricity transmission towers in China. However, there is still lack of information on the behaviour of such kind of members. This paper thus carried out the investigation on axially loaded tapered CFDST stub columns. The parameters included the tapered angle and the sectional profile. A finite element analysis (FEA) model was developed to predict the behaviour of the tapered member as well. The results showed that the steel tubes and the sandwiched concrete could work together well despite the tapered angle. The failure mode of the tapered CFDST stub column was similar to that of the straight one, and the failure occurred near the smallest section. The confinement effect of the tapered member was discussed by using the stress analysis. Finally, formulas were suggested for the calculation on the ultimate strength of the tapered CFDST stub column.     

Analysis and calculations of steel tube confined concrete (STCC) stub columns

The use of steel tube confined concrete (STCC) columns has been the interests of many structural engineers. A finite element analysis (FEA) model was established in this paper to analyse the mechanisms of STCC stub columns under axial compression. It was found that both the predicted ultimate strength and load versus deformation curves show generally good agreements with those of the measurements. The interaction between the steel tube and its concrete core was analysed and illustrated by using the FEA model. Simplified formulae were proposed by using the regression method based on the parametric analysis outcome.