共查询到19条相似文献，搜索用时 174 毫秒
1.
曲线桥梁抗震特性模拟分析对于曲线桥梁隔震、减震有着重要意义。基于隔震曲线桥梁设计过程中的特点,通过非线性水平弹簧单元对铅芯橡胶支座双向非线性的能力进行模拟,根据SAP2000科学选择强震观测地震波,并考量曲线桥梁本身存在的特性对桥梁振动特性产生的影响,针对隔震曲线桥梁在不同等级地震下振动特征进行模拟分析,其中,通过隔震曲线桥梁铅芯橡胶支座模型的构建和梁桥不同等级地震计算模型、输入地震波与传感器量测等步骤得到的模拟结果为:不同地震波与加速度峰值输入过程中,地震动较小下的支座水平刚度比较大,且结构相对稳定;地震幅值增大时,桥梁支座水平刚度减小,且支座的恢复力位移滞回变化曲线面积比较大,能够更多地将地震输入能量消散掉,减小能量不断向曲线桥梁上方传递的速度,可有效减轻地震反应,起到隔震的效果。 相似文献
2.
低硬度橡胶隔震支座基本力学性能及恢复力特性 总被引：4，自引：2，他引：4
本研究对低硬度橡胶隔震支座的材料性能（主要包括力学性能）进行了系统的试验开发及理论研究。研究用低硬度橡胶隔震支座包括天然橡胶隔震支座及铅芯橡胶隔震支座两大类18种规格总计近30个大直径隔震支座。研究内容涉及橡胶隔震支座竖向刚度、水平刚度及阻尼等基本力学性能；压缩界限，屈曲及极限剪切变形等界限性能；温度、压力、剪切变形、老化和徐变等相关性及长期特性；同时还对橡胶材料其他性能进行了系统的试验研究。本文主要介绍低硬度天然橡胶隔震支座及铅芯橡胶隔震支座的基本力学性能，如竖向、水平刚度和恢复力等特性。 相似文献
3.
《地震工程与工程振动》2020,(4)
道庆洲桥是一座公轨两用双层变高钢桁组合桥梁,采用双曲面球型减隔震支座。该支座的竖向承载力为135 000 kN,超出桥梁双曲面球型减隔震支座规范的正常标准。为了研究此桥的抗震性能及其支座性能,本文设计和制作了安装有与实桥支座的竖向承载力相似比为1∶25的双曲面球型减隔震支座的双层变高度钢桁梁节段的缩尺模型,对其进行拟静力试验。得到了整个模型在不同支座轴压比下的滞回曲线、骨架曲线、刚度和水平承载力退化、耗能能力和滑动摩擦系数等抗震性能指标。试验结果表明:不同支座轴压比下,模型的滞回曲线饱满,呈现为平行四边形;与普通双曲面球型减隔震支座相比,支座的滞回性能相同;随着支座轴压比的增加,模型的水平承载能力、累积耗能、初始刚度和滑动摩擦系数也会相应增加,但对于水平承载力退化、刚度退化和等效黏滞系数影响较小;试验模型具有良好的抗震性能。 相似文献
4.
《地震工程与工程振动》2015,(6)
钢丝网复合橡胶减隔震支座是一种可以翘曲滚动实现剪切大变形的新型减隔震支座,主要适用于中小跨径桥梁。为了探究钢丝网复合橡胶减隔震支座的减隔震性能及恢复力特性,本文对其进行拟静力试验,得到支座滞回曲线,反映出较好的耗能能力,在试验数据基础上利用最小二乘法拟合提出支座的三段线性恢复力模型;为了推广该支座的实桥应用,实现其在实桥抗震验算有限元建模中的模拟,本文在SAP2000有限元程序中采用多段线性塑性连接单元的Kinematic模型模拟支座,重现拟静力试验加载过程,对比支座有限元计算滞回曲线和试验滞回曲线,模拟结果良好。 相似文献
5.
方形多铅芯橡胶支座力学性能研究 总被引：7，自引：0，他引：7
本文通过对方形多铅芯橡胶支座竖向压缩性能试验,水平剪切性能试验以及其等效刚度、屈服强度、屈服后刚度、等效阻尼比等水平特征参数与水平剪切应变和竖向压应力的关系,特别是对其在不同方向上压缩剪切变形状态下的性能试验,分析了这种隔震支座各种水平特征参数在不同方向上变化的相关规律。得出在这种类型橡胶隔震支座在双向水平荷载同时作用下,竖向性能和水平性能较为稳定,是较为理想的桥梁结构的减隔震装置。 相似文献
6.
中国铅芯夹层橡胶隔震支座各种相关性能及长期性能研究 总被引：5，自引：1，他引：5
本文详细地研究了各种相关因素对中国铅芯橡胶隔震支座力学性能的 影响，同时还研究了中国铅芯夹层橡胶隔震支座的长期性能。研究包括竖向压力、频率、剪切变形循环次数、温度对隔震支座刚度及阻尼等力学性能的影响；隔震支座的耐久性能诸如老化及徐变对隔震器刚度、阻尼特性及极限变形能力的影响。研究还包括水平剪切（200次）及竖向低周疲劳（10万次）试验对隔震器力学性能的影响。 相似文献
7.
橡胶隔震支座竖向刚度简化计算法 总被引：12，自引：5，他引：12
本文提出了采用橡胶隔震支座刚度因子计算隔震支座竖向刚度的方法，在此基础上提出了适于工程应用的简化计算式，研究还进行了2种不同橡胶6种规格共12件试验体的竖向刚度及水平刚度试验。文末给出了该计算结果与试验结果的对比，表明本文所提计算方法适合于工程使用。 相似文献
8.
为研究温度对铅芯橡胶支座(LRB)性能的影响,进行支座拟静力试验。试验表明,在不同温度环境中试件的滞回曲线明显不同,支座的刚度和屈服剪力均随温度的升高而降低;低温时,支座的力学特性变化较大,而当温度大于20℃时,支座的力学特性趋于稳定。以某五层基础隔震建筑为例,编写基础隔震结构非线性时程分析程序NBIS,计算该隔震建筑在考虑温度影响后的地震响应。结果表明,在多遇地震作用下支座恢复力随温度的升高而降低,与罕遇地震下的变化趋势相反;考虑LRB温度影响后,该基础隔震结构的减震系数随环境温度的降低而增大,支座的最大位移随温度升高而增大。 相似文献
9.
通过三维隔震墩的拟静力试验研究其水平刚度,将试验结果与三维隔震墩的设计理论值进行比较。结果表明:试验结果与设计理论值相对误差在[7.4%24.4%]之间,验证了该隔震装置设计理论的合理性。利用ANSYS建立4层框架结构隔震与非隔震模型并进行时程分析,研究三维隔震墩的隔震性能。有限元对比分析结果表明:在考虑竖向地震动三维耦合作用情况下,框架梁截面竖向剪力增大,多层房屋的竖向地震动作用不可忽略;在输入不同地震动情况下,可以将水平加速度有效衰减40%以上,梁截面内力减小30%以上,该隔震装置的隔震性能良好。 相似文献
10.
低硬度橡胶隔震支座各种相关性及老化徐变特性 总被引：4，自引：1，他引：4
作者系统地对低硬度橡胶隔震支座的材料和力学性能进行了试验研究。研究使用的低硬度橡胶隔震支座分18种规格，总计近30个大直径隔震支座。研究内容涉及低硬度橡胶隔震支座的基本力学性能；温度、压力、剪切变形、老化和徐变等相关性；压缩界限，屈曲及极限剪切变形等界限性能以及橡胶材料性能和隔震工程应用等方面。本文主要介绍低硬度橡胶隔震支座的压力、剪切变形、温度对支座刚度、阻尼等力学性能的影响，同时还对隔震支座的老化及徐变特性进行了试验研究，确定低硬度橡胶使用60年后的力学性能变化率。文中同时提出了低硬度橡胶支座的温度修正方程，并提出了隔震结构地震反应分析时支座刚度和屈服荷载变化的取值范围。 相似文献
11.
Unbonded fibre‐reinforced elastomeric isolator (U‐FREI) is relatively new seismic base isolator in which fibre layers are used as reinforcement to replace steel shims as are normally used in conventional isolators. Further, the top and bottom end steel connector plates of conventional isolators are also removed. In general, the horizontal response of U‐FREI is nonlinear because of reduction in contact area due to rollover deformation and reduction in shear modulus of isolator under large deformation. Thus, evaluation of horizontal stiffness of U‐FREI is a challenging problem. Most previous studies were focused on the investigation of horizontal response of scaled models of U‐FREIs with low shape factors. A few analytical approaches were suggested for predicting the horizontal response of U‐FREI; but their results were not in good agreement with experimental observations. In the present study, the horizontal responses of prototype U‐FREIs are evaluated under a constant vertical pressure and cyclic loading using both experiments and finite element analysis. Prototype U‐FREIs with different shear moduli and with different shape factors are considered. Finite element simulations of corresponding bonded FREIs are also performed under the same loadings as in U‐FREIs. A rational analytical approach including the influence of rollover deformation and simultaneous reduction in shear modulus is proposed as a basic analytical tool for predicting the horizontal stiffness of FREIs (both bonded and unbonded). It is in reasonably good agreement with the results obtained from experiments and numerical analysis. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
12.
变刚度钢管混凝土短柱隔震装置的性能研究 总被引：7，自引：1，他引：6
本文对变刚度钢管混土短柱震的滞回收性进行了理论分析和试验验证。对装置的隔震作用以及耗能特性进行了讨论通过低周反复荷载试验,证了分析的正确性。同时,试验还证明,变刚度钢管混凝土短柱震装置能很好的地耗散能量,从而减小地震反应,作者认为,该是一种价格性能比较优越的隔震装置,在工程实践中将有广阔的应用与推广前景。 相似文献
13.
采用大型通用有限元程序,对低硬度大直径橡胶隔震支座在竖向荷载作用下的基本性能进行了精细有限元分析。分析了在竖向荷载作用下支座上下封板、内部钢板的各种应力分布,以及支座顶部是否施加竖向同位移约束、支座孔径比、橡胶材料G值、内部单层橡胶厚度与内部单层钢板厚度之比对支座内钢板受力的影响。结果表明,内部钢板最大Mises应力、最大径向水平正应力约为支座竖向压力的4倍、2.5倍;支座顶部是否施加竖向同位移约束对支座用钢板内力影响较大,特别是支座上封板;橡胶G值的变化对内部钢板受力基本没影响;支座孔径比对靠近孔边缘部分内部钢板应力不均匀性分布影响较大;内部单层橡胶厚度与内部单层钢板厚度的比值对内部钢板的Mises应力、径向正应力、环向正应力影响较大,但对其竖向正应力基本没影响。 相似文献
14.
This paper presents an experimental research aimed at developing a new rubber‐based seismic isolator called ‘Ball Rubber Bearing (BRB)’. The BRB is composed of a conventional steel‐reinforced multi‐layered rubber bearing with its central hole filled with small diameter steel balls that are used to provide energy dissipation capacity through friction. A large set of BRBs with different geometrical and material properties are manufactured and tested under reversed cyclic horizontal loading at different vertical compressive load levels. Extensive test results indicate that steel balls do not only increase the energy dissipation capacity of the elastomeric bearing (EB), but also increase its horizontal and vertical stiffness. It is also observed that the energy dissipation capacity of a BRB does not degrade as the number of loading cycles increases. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
15.
T形钢管混凝土柱与钢梁外伸端板连接节点抗震性能试验研究 总被引：1，自引：0，他引：1
本文对3个T形钢管混凝土柱与钢梁外伸端板连接节点进行了低周反复荷载作用下的试验研究及分析,研究外伸端板连接节点破坏形式及抗震性能。分析结果表明:该类节点的强度主要取决于高强螺栓的强度及外伸端板的强度和刚度,高强螺栓强度和外伸端板厚度的不同直接影响节点的性能;该类节点具有较好的耗能性能,强度较高。这些研究结果对外伸端板连接节点的研究和应用提供了一定的理论基础。 相似文献
16.
Alan D. Hewitt 《Ground Water Monitoring & Remediation》1994,14(1):87-94
Experiments simulating the dynamics of compliance sampling via a monitoring well were performed to assess the effects of common well screen materials (rigid polyvinyl chloride, polytetrafluoroethylene, stainless steel 304. and stainless steel 316) on several metals and tri- chloroethylene (TCE) in ground water. This was achieved by using a continuous flow-through chamber system capable of exposing monitoring well screens to ground water for periods ranging from 0.25 to 8 hours. The findings of this study are more representative than static laboratory experiments for assessing the potential effects well casing materials have on ground water samples. Under dynamic flow conditions stainless steel 304 and 316 screens were found to influence solution concentrations of Pb, Cd, Cr, Ni, and Fe, while ground water TCE concentrations were not affected by any of the materials tested. 相似文献
17.
钢管混凝土短柱隔震装置的试验与隔震结构仿真分析 总被引：3，自引：0，他引：3
本文阐述了钢管混凝土短柱装置的工作原理,给出了装置的构造,对隔震装置的试验结果进行了详细分析,并对传统结构模型与隔震结构模型的对比实验作了仿真计算与分析．从计算结果可知,钢管混凝土基底隔震装置具有良好的隔震性能和推广使用价值。 相似文献
18.
This paper extends the scope of seismic isolation by introducing an innovative uplift‐restraining Friction Pendulum system. Termed the XY‐FP isolator, the new isolation device consists of two orthogonal opposing concave beams interconnected through a sliding mechanism that permits tension to develop in the bearing, thereby preventing uplift. Owing to its distinct configuration, the XY‐FP isolator possesses unique properties for a seismic isolator, including uplift restraint, decoupling of the bi‐directional motion along two orthogonal directions, and capability of providing independent stiffness and energy dissipation along the principal horizontal directions of the bearing. The study concentrates on introducing the concept and establishing the underlying principles of operation of the new XY‐FP isolator, formulating the mathematical model for the XY‐FP isolator, and presenting its mechanical behaviour through a displacement‐control testing program on a single XY‐FP isolator. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
19.
The use of base isolation in developed countries including the U.S. and Japan has already been recognized as a very effective method for upgrading the seismic resistance of structures. In this study, an advanced base‐isolation system called the multiple friction pendulum system (MFPS) is investigated to understand its performance on seismic mitigation through full‐scale component and shaking table tests. The component tests of the advanced Teflon composite coated on the sliding surface show that the friction coefficient of the lubricant material is a function of the sliding velocity in the range of 0.03–0.12. The experimental results also indicate that there were no signs of degradation of the sliding interface observed after 2000 cycles of sliding displacements. A full‐scale MFPS isolator under a vertically compressive load of 8830 KN (900 tf) and horizontally cyclic displacements was tested in order to assess the feasibility of the MFPS isolator for its practical use. After 248 cycles of horizontal displacement reversals, the behaviour of the base isolator was almost identical to its behaviour during the first few cycles. The experimental results of the shaking table tests of a full‐scale steel structure isolated with MFPS isolators show that the MFPS device can isolate seismic transmitted energy effectively under soft‐soil‐deposit site earthquakes with long predominant periods as well as strong ground motions with short predominant periods. These test results demonstrate that the MFPS isolator possesses excellent durability and outstanding earthquake‐proof capability. Furthermore, the numerical results show that the mathematical model proposed in this study can well predict the seismic responses of a structure isolated with MFPS isolators. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献