【作者】 刘斌；

【导师】 刘艳辉；

【作者基本信息】 西南交通大学 ， 结构工程， 2015， 硕士

【摘要】 随着现代化进程的加快与铁路运输需求的激增,列车的营运密度和速度都迅速提高；列车脱轨成为火车运行的一大安全隐患,对于铁路客站这类人员密集的大型交通枢纽,一旦列车发生脱轨事故,不仅是结构造成破坏,更有可能危害站内人员的安全,其次生灾害难以想象。通过调查统计,张弦梁雨棚结构所占的比例比较大,为追求站房内通透性,较多站房结构选择将柱子设在站台下,这也给火车脱轨后撞击站台柱留下了一定的安全隐患,并且此类结构一般冗余度较低,抵抗连续性倒塌的能力较弱,因此对张弦梁雨棚结构在脱轨列车撞击作用下的动力响应的研究迫在眉睫。本文数值模拟是由LS-DYNA软件进行火车与张弦梁雨棚结构的撞击计算,对张弦梁结构撞击作用下动力响应做了分析,比较了不同边界条件、不同撞击初速度对撞击作用下张弦梁动力响应的影响。论文的主要研究内容及研究成果如下：1.上部张弦梁结构应力的响应是有一定的滞后时间的,虽然时间间隔很短。并且能量的传递是以最先接触到外荷载的部分为中心向周围传递的,某种程度上类似地震发生时地震波的传递,上部结构在该能量波的作用下做来回的振动,并且由于自身的阻尼作用,振动的幅度会越来越小,最后直至静止；2.列车撞击初速度5.22m/s-11.75m/s范围内为安全范围,上部张弦梁结构不会发生破坏,材料不会屈服,腹杆不会发生失稳；当列车以7.83m/s的速度与不同边界条件站房结构柱发生撞击时,站房结构不会发生破坏。3.虽然在列车80km/h的脱轨初速度撞击下,上部梁没有发生剪切破坏,但不排除列车高速撞击,产生更大剪切应力的可能。为防止梁发生剪切破坏,可以加强梁端部截面抗剪强度。由于绕Y轴弯矩远大于绕Z轴弯矩,为减小梁截面撞击荷载作用下弯曲正应力,可以改变截面尺寸或形状,适当增大截面Y轴惯性矩。4.简支型张弦梁结构连接节点、梁单元、索单元的内力均大于连续型张弦梁。连续型张弦梁结构抵抗撞击荷载性能比简支型强。5.当索内预应力值由500kN损失变为250kN时,结构不会发生破坏,材料仍处于弹性阶段,但结构的最大位移增加了31.7%,最大轴应力增加了13.2%,最大切应力基本不变。更多还原

【Abstract】 Around the world in the 21st century frequent train derailment accident and causing heavy casualties and economic losses, structural damage occurred in the open air derailment caused by the accident is not yet have continuity, for the railway station of such personnel-intensive large-scale transportation hub, train tracks throughout the interior passenger station, the train derailment accident once, not only will damage the structure, the structure is more likely to lead to progressive collapse, followed by raw unimaginable disaster.Through the survey, both in the domestic high-speed rail passenger station canopy structure, beam string proportion of canopy structure is relatively large, the permeability of the room for the pursuit of the station, the station house structure more choice in the column under the site, which but also to derail the train station pole crash left a security risk, and that such structures are generally less redundancy, more independent, the ability to resist progressive collapse is weak, so the beam string canopy structure in effect derailed train crash study the dynamic response under imminent.Numerical simulation of this paper is to set up and use the finite element mesh hypermesh10.0 by AUTOCAD2012, boundary conditions by LS-PREPOST (LS-DYNA common front processor) were applied by the LS-DYNA software locomotive and canopy structure of Beam String calculate the impact of the strike action under the structural dynamic response of beam string to do the analysis, comparison of the different boundary conditions, the impact of the early impact of the different impact velocities under dynamic Response. The main contents and research results are as follows:1. Collision velocity greater impact on the internal forces, which will affect the impact of substance with the impactor mass maximum internal force is relatively small.2. Structural stress response is a certain lag time, although very short time interval. And the transfer of energy is the first contact to the outer part of the load transfer to the surrounding of the center, similar to some extent to pass when the earthquake seismic waves, vibrating back and forth under the action of the upper structure made of the energy waves, and due to its the damping effect, the magnitude of vibration will become increasingly smaller, until finally resting.3. Initial speed train crash 5.22m/s-11.75m/for the safe range, the upper beam string structure will not damage occurred within the scope of s, the material does not yield, webs instability does not occur.4. When the train at a speed of 7.83m/s with different boundary conditions the station house structural columns collision occurred, the station house construction will not damage occurred.5. Simply supported beam structure type string connecting nodes, internal force beam elements, cable elements are larger than the continuous beam string, webs opposite internal forces. Continuous beam string structure to resist impact load performance is stronger than simply supported type更多还原