共查询到20条相似文献,搜索用时 78 毫秒
1.
大跨度悬索桥梁端竖向折角对列车走行性的影响研究 总被引:1,自引:0,他引:1
大跨度桥梁较为柔性,易产生梁端竖向折角,过大的梁端竖向折角会影响列车的安全性和舒适性。有代表性地选取较为柔性的大跨度公轨两用悬索桥作为工程背景,基于车-桥耦合动力仿真数值计算方法,采用自主研发的桥梁科研分析软件BANSYS(Bridge ANalysis SYStem),分析列车进桥及出桥全过程中车辆和桥梁的响应,对比不同车辆运行方式、不同车速、不同车载状态下的响应,讨论大跨度悬索桥梁端竖向折角对列车走行性的影响,进一步提出减小梁端竖向折角的措施。研究结论对大跨度轨道交通桥梁的运营安全具有指导意义。 相似文献
2.
考虑栓钉连接件的柔性,针对一座3跨钢-混凝土铁路连续结合梁实桥建立有限元模型,对其自振特性进行分析,并与试验结果进行对比。经研究发现:柔性栓钉连接件所引起的滑移对结合梁的动力响应有重要影响。基于上述分析,进行了高速列车荷载作用下结合梁动力响应分析,计算了桥梁和车辆的各种动力指标的最大值:包括冲击系数、桥梁的竖向和横向动位移及动加速度、机车和车辆的脱轨系数、轮重减载率、横向和竖向加速度及横向和竖向平稳性指标(Sperling指标),并与实测结果进行了对比,结果吻合较好。 相似文献
3.
基于风-车-桥(线)耦合振动的风屏障防风效果研究 总被引:1,自引:0,他引:1
为考察风屏障的防风效果,通过风洞试验测试平地路基、高路堤、桥梁三种典型线路上设置不同风屏障情况下车辆的气动力系数,采用风-车-桥(线)耦合振动的分析方法研究车辆的动态响应,讨论风屏障高度、车辆线路位置及线路构造形式等因素的影响。结果表明,风屏障可有效地降低强风作用下车辆的响应,平地路基上设置2.05m风屏障时,车辆运行的瞬时临界风速可达50m/s;车辆的轮重减载率、倾覆系数及竖向加速度对车辆线路位置较为敏感;线路构造形式对背风侧车辆响应影响较大,风屏障高度相同时,高路堤上的防风效果较好。 相似文献
4.
5.
6.
7.
为防止隔震层在极罕遇地震作用下出现过大变形而导致隔震设施损坏,部分隔震结构安装了钢墩或钢筋混凝土墩等刚性限位装置。为了研究刚性限位对基础隔震结构动力响应的影响,设计三层单跨钢框架基础隔震结构以及钢墩、钢筋混凝土墩、带橡胶垫层钢墩三种刚性限位器,并进行振动台试验。研究不同预留间隙时三种限位器对基础隔震结构的位移、加速度、接触力以及隔震支座竖向荷载等动力响应影响的规律。试验结果表明,刚性限位器能有效减小其隔震层位移,但也会对上部楼层产生较高大的不利响应,同时会增大隔震支座的竖向荷载,甚至使支座产生拉应力。在钢墩前设置橡胶垫层能明显减小上部结构的加速度响应,对上部结构位移响应、隔震支座竖向力及碰撞点处接触力影响不大。 相似文献
8.
斜拉桥是一种特殊结构的桥梁,其特殊之处就在于可以给定一个拉索的初拉力,这个拉力会改变整个斜拉桥结构体系的内力和变形以及各个部件的受力,但是影响斜拉桥内力的因素还有很多,比如说辅助墩。对于斜拉桥这样的大跨度超静定体系,地震、台风以及车辆移动荷载等动力激励的作用下动力反应较为敏感,所以研究斜拉桥的动力响应对其是非常重要的。本文以某斜拉桥为例分析了辅助墩对斜拉桥活载响应的影响,活载作用下辅助墩设置的合理位置,以及辅助墩对斜拉桥动力特性和地震响应的影响。 相似文献
9.
本文以一座主跨850m的大跨双塔悬索桥为工程背景,采用时程分析法研究了行波效应大跨双塔悬索桥地震响应的影响。通过建立三维有限元分析模型,在分析了大跨度双塔地锚式悬索桥动力特性及一致激励下地震响应规律的基础上,进一步探讨了行波效应对大跨双塔地锚式悬索桥地震响应的影响规律。分析结果表明:地震波纵向行波作用下,主塔的地震响应随着视波速的减小而先减小后增大;主梁的竖向振动则较一致激励下显著增大;主缆及吊索轴力则受地震动行波效应的影响不大。 相似文献
10.
11.
André Bégin-Drolet Jean Ruel Jean Lemay 《Journal of Wind Engineering & Industrial Aerodynamics》2011,99(8):825-832
The main objective of this article is to analyze the angular (off-axis) response of heated cup anemometers designed specifically for wind power generation in cold climate. Three commercial heated cup anemometers are tested together with two ice-free prototypes developed as part of a broader research program focusing on ice-free sensors. Three indexes are proposed to allow better data analysis of angular response measurements. It is shown that careful attention to the anemometer geometry can lead to a nearly perfect cosine shape response while improper rotor geometry can lead to very bad angular response. A patented rotor geometry design is tested on different anemometers to see if one could expect the desired angular response for cup anemometers used in the wind energy industry to be obtained with such rotor geometry. 相似文献
12.
13.
A three-dimensional finite element analysis has been used to simulate the coupled static and dynamic behaviour of compliant ocean structures. Nonlinearities which result from large deflections, reduced or zero stiffness in compression, and nonconservative fluid loading are considered. The spatial variation of fluid loading is also addressed. The structures are assumed to be in the Morison regime. Linear wave theory is used and multidirectional seas may be simulated. A variable current profile may be specified and concentrated masses and loads, as well as foundation properties, may be modelled. Updated Lagrangian coordinates and a residual feedback, incremental-iterative, solution is adopted. Viscous relaxation is used to start the static solution of problems with small initial stiffnesses. The dynamic solution is performed in the time domain and uses the Newmark integration scheme. Consistent mass matrices are developed for both beam-column and cable elements. The directionality of the hydrodynamic added mass is accounted for, as is the discontinuity of the mass density for elements which pierce the water surface. Examples are presented of an articulated tower, of a guyed tower, and of a tension leg platform. 相似文献
14.
通过对地震行波效应的研究,推导了时间相关的行波反应谱,并对行波反应谱的应用前景进行了展望,指出行波反应谱比传统的做法更为合理、经济,值得推广应用。 相似文献
15.
16.
17.
18.
《The IES Journal Part A: Civil & Structural Engineering》2013,6(4):211-223
Long-period ground motions with directivity and/or path effects are often characterised by the presence of velocity and acceleration pulses in the lowermost frequency range. An objective of this article is to present a discrete-time signal processing method for isolating these pulses. In this method, the velocity and the acceleration pulses are identified by applying a low-pass discrete-time filter Hlp (ω) at a suitable cut-off frequency f c to the Fourier transforms of the original velocity and acceleration ground motion time histories, respectively. Another objective of this article is to present a mathematical expression for evaluating the linear displacement response of a single degree-of-freedom (SDF) system by simultaneous application of two frequency modulators, Hlp (ω) and Hu (ω), to the original ground excitation. By using only the pulse component of the ground motion as the excitation force, it is shown that the displacement response of the SDF system with natural period exceeding a certain value referred to as the cut-off period T c is quite comparable with that due to the original ground excitation. Also, for ground motions that contain multiple-period pulses, it is shown that the displacement response spectrum of the SDF system exhibits multiple peaks at different natural system periods T n. 相似文献
19.
Emil Simiu 《Engineering Structures》1983,5(4):273-281
This is the fourth in a series of review papers devoted to the state-of-the-art in wind engineering. The first three parts of the series were published in the October 1981 (pp. 233–241 and 242–248) and March 1982 (pp. 66–74) issues of Engineering Structures. 相似文献
20.
应用国际通用的CAARC模型进行了多自由度气动弹性模型在模拟风场中响应的试验,分析了结构在不同风速与不同风向角下的顺风向响应与横风向响应变化规律,所得到的结果为高层建筑结构的风振响应理论提供参考. 相似文献