大跨钢结构枢纽站房连续性倒塌数值仿真分析

发布时间：2018-11-17 20:21

【摘要】：目前国内外防连续倒塌设计方法的研究主要基于规则框架,对大跨枢纽客站抗连续倒塌的计算方法和影响因素等都缺乏足够的研究基础。且以往学者大多采用静力分析方法,这对于连续倒塌分析的结果有失逼真。本文采用ANSYS/LS-DYNA有限元程序对某大跨钢结构站房进行连续倒塌动力响应仿真分析,以深入了解大型铁路客站结构的连续倒塌机理。首先运用平均应力比法和能量法对该工程的关键柱子进行了选择;然后运用等效荷载瞬时卸载法对该结构在不同关键柱子及根数失效工况下的缺陷结构进行了动力仿真分析,从而判断结构在每种工况下的倒塌情况;对各工况下结构的上部网壳层和下部高架层的响应分别作了对比;最后参数化分析了材料失效应变、等效荷载失效时间、阻尼比等因素对结构连续性倒塌的影响。在各种工况下结构均没有发生连续倒塌,说明该工程具有很好的冗余度及防止连续倒塌的能力。结构的双根中柱失效对下部高架层的不利影响最大,双根边柱失效对上部网壳层的不利影响最大。参数化研究表明,对于本工程,材料失效应变在弹性极限与塑性极限之间变化对于单根边柱失效的倒塌仿真分析结果影响不大;等效荷载失效时间取为缺陷结构第一阶竖向自振周期的1/10为最合理值;阻尼比在一般钢结构阻尼比取值之间变化对该结构的倒塌性能没有太大影响。
[Abstract]:At present, the research on the design methods of continuous collapse prevention is mainly based on the rule framework, and there is a lack of sufficient research foundation for the calculation method and influencing factors of the anti-continuous collapse of the passenger station of the large span hub. In the past, most scholars used static analysis method, which is not realistic for the results of continuous collapse analysis. In this paper, ANSYS/LS-DYNA finite element program is used to simulate the continuous collapse dynamic response of a large span steel station building, in order to understand the continuous collapse mechanism of large railway passenger station structure. Firstly, the key columns of the project are selected by using the average stress ratio method and the energy method. Then the dynamic simulation analysis of the defective structure under different key columns and root number failure conditions is carried out by using the equivalent load instantaneous unloading method to judge the collapse of the structure under each condition. The responses of the upper latticed shell layer and the lower elevated layer of the structure under different working conditions are compared respectively. Finally, the effects of material failure strain, equivalent load failure time and damping ratio on the continuous collapse of the structure are analyzed by parameterization. There is no continuous collapse of the structure under various working conditions, which indicates that the project has good redundancy and the ability to prevent continuous collapse. The failure of the double mid-column has the most adverse effect on the lower layer of elevated structure, and the failure of the double-root side column has the most adverse effect on the upper layer of the reticulated shell. The parameterized study shows that the variation of material failure strain between elastic limit and plastic limit has little effect on the collapse simulation results of single edge column. The failure time of equivalent load is taken as 1 / 10 of the first vertical natural vibration period of the defective structure, and the change of damping ratio between the damping ratios of general steel structures has little effect on the collapse performance of the structure.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU391;TU312.3

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