实际火灾作用下门式刚架抗火性能研究

发布时间：2018-04-11 03:14

本文选题：门式刚架 + 实际火灾　；参考：《东南大学》2016年硕士论文

【摘要】：门式刚架结构具有受力简单、便于工厂化加工、造价低等特点,在工业与民用建筑中被广泛应用。然而,该结构通常空间宽敞,通透性较好,当可燃物较多时,一旦失火,在空气对流的作用下,火势发展迅速,很容易造成结构破坏甚至倒塌。因此对实际火灾下该类结构的力学性能开展研究,进而提出科学合理的设计建议,具有重要的理论价值和实际意义。目前对于门式刚架的抗火性能研究主要采用静力分析的方法,然而,该方法不易收敛,难以有效模拟结构的破坏过程。同时在火灾下门式刚架试验研究的基础上进行门式刚架数值模拟较少,且对门式刚架整体结构的抗火性能研究不多。针对上述问题,本文进行了如下工作：(1)在总结大空间实际火灾的特点、火灾荷载确定方法以及火灾仿真技术的基础上,采用场模拟软件FDS建立不同的火灾场景模型,对门式刚架厂房进行火灾仿真分析。(2)采用ABAQU S建立引入能量耗散系数的拟静力分析方法,通过运用此方法分析折梁模型,分别与静力法、动力法对比,结果表明引入能量耗散系数的拟静力法能够克服因失稳带来的不收敛问题,同时能够较好的模拟出结构的临界温度及耐火时间。(3)基于ABAQUS采用拟静力法对本课题组已开展的门式刚架整体结构抗火试验进行数值模拟,并与试验结果对比分析。结果表明三维整体模型仿真因考虑结构整体协同作用,分析结果与试验值吻合较好,本文的有限元分析方法得到了验证。(4)采用ABAQUS对《门式刚架轻型房屋钢结构》(02SG518-1)中的三种典型门式刚架整体结构的抗火性能进行分析,给出实际火灾作用下的整体结构倒塌模式及临界温度,同时对发生侧移破坏的结构的防火保护措施、柱脚刚度问题进行了讨论。根据分析结果,提出了门式刚架结构的抗火设计建议。
[Abstract]:Portal frame structure is widely used in industrial and civil buildings because of its simple force, easy industrial processing and low cost.However, the structure usually has large space and good permeability. When there are more combustible materials, the fire develops rapidly under the action of air convection, which can easily lead to the destruction or even collapse of the structure.Therefore, it is of great theoretical value and practical significance to study the mechanical properties of this kind of structures under actual fire, and to put forward scientific and reasonable design suggestions.At present, the static analysis method is mainly used to study the fire resistance of portal frames. However, this method is difficult to converge and can not effectively simulate the failure process of structures.At the same time, the numerical simulation of portal frame is less based on the experimental study of portal frame under fire, and the fire resistance of the whole structure of portal frame is not much studied.Aiming at the above problems, this paper has done the following work: 1) on the basis of summarizing the characteristics of the actual fire in large space, the method of determining the fire load and the fire simulation technology, the field simulation software FDS is used to establish different fire scene models.The fire simulation analysis of portal frame factory building is carried out. (2) A pseudo-static analysis method with energy dissipation coefficient is established by using ABAQU S, and the beam folding model is analyzed by using this method, which is compared with static method and dynamic method, respectively.The results show that the quasi-static method with energy dissipation coefficient can overcome the problem of unconvergence caused by instability.At the same time, the critical temperature and fireproof time of the structure can be simulated well. (3) based on ABAQUS, the numerical simulation of the fire resistance test of portal frame has been carried out by using the pseudo-static method, and the results are compared with the test results.The results show that the analysis results are in good agreement with the experimental data due to the consideration of the overall synergy of the structure.The finite element analysis method in this paper has been verified. (4) ABAQUS is used to analyze the fire resistance of three typical portal frame integral structures in "light building steel structure of portal frame" (02SG518-1).The collapse mode and critical temperature of the whole structure under the action of actual fire are given. At the same time, the fire protection measures and the stiffness of the column foot for the structure with lateral displacement failure are discussed.According to the analysis results, the fire resistance design suggestion of portal frame structure is put forward.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TU392.5;TU352.5

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