【作者】 王丽；

【导师】 周林聪；

【作者基本信息】 吉林大学 ， 结构工程， 2018， 硕士

【摘要】 近些年来,我国建筑结构火灾发生的频率越来越高,建筑火灾造成的损失也越来越大。钢筋混凝土建筑结构在火灾及高温情况下,各项性能随温度的升高有不同程度的降低,导致结构抗火性能下降,危及结构的安全性。鉴于这种情况,深入分析钢筋混凝土结构在火灾高温情况下的温度场分布,进行结构场分析,以得到温度场和结构场的影响因素,为结构的抗火分析提供指导作用。本文主要进行了以下工作:(1)本文详细叙述了国内外关于抗火研究方面的研究成果,火灾高温情况下混凝土、钢筋的热工性能和力学性能,为火灾模拟提供理论数据。一方面由于建筑火灾的随机性特别大,另一方面影响材料性能参数的因素众多,因此对结构构件进行温度场和结构场分析时,需要对钢筋和混凝土材料的本构关系作一些基本假设。(2)本文应用FDS火灾模拟软件,建立办公楼火灾数值分析模型,分析得到不同温度观测点的升温曲线,切片的温度场分布,火灾的热释放速率曲线等。由于实测的火灾升温曲线和标准升温曲线存在较大的不同,因此对结构构件进行真实火场下温度场结构场分析时,本文采用实测的升温曲线。(3)将FDS得出的实测升温曲线作为数据基础,应用到ANSYS有限元分析软件进行热-力耦合分析。即首先进行截面温度场的分析,在温度场分析的基础上,再进行结构场分析,研究火灾高温下钢筋混凝土构件截面温度场和变形性能的影响因素,为火灾发生情况下钢筋混凝土结构的抗火性能分析奠定基础。更多还原

【Abstract】 In recent years,the frequency of building fires is increasing in China,and the losses caused by building fires are also increasing.Under the high temperature of the fire,the properties of the reinforced concrete structure decrease with the increase of temperature,which leads to the decrease of fire resistance and the safety of the structure.In view of this situation,the temperature field of reinforced concrete structure under the condition of fire and high temperature is analyzed,and the structural field analysis is carried out,and the influence factors of the temperature field and the structure field are obtained,which can provide guidance for the fire resistance analysis of the structure.The following work is carried out mainly;(1)The results of the high temperature research at home and abroad,the thermal and mechanical properties of the materials at high temperature are described in detail in this paper,which provide theoretical data for the next fire simulation.On the one hand,the randomness of the building fire is very large,and on the other hand,there are many factors affecting the performance parameters of the material.Therefore,when the temperature field and the structure field are analyzed,some assumptions about the constitutive relation of the reinforced concrete and the concrete materials are needed.(2)Different building structures have different fire conditions.In this paper,the FDS fire simulation software is used to establish an office building fire numerical analysis model,and the heating curve of different temperature observation points,the distribution of the temperature field of the slice,the heat release rate curve of the fire are analyzed.The measured temperature rise curve and the standard temperature rise curve are different,so the measured temperature rise curve is used in the analysis of the structure field of the temperature field under the real fire field.(3)Taking the measured temperature rising curve from FDS as the data basis,the thermal force coupling analysis is applied to the ANSYS finite element analysis software.On the basis of the analysis of temperature field,the analysis of structure field is carried out on the basis of the analysis of temperature field,and the influence factors of the temperature field and deformation properties of reinforced concrete beams under fire are studied,which lays a foundation for the fire resistance analysis of reinforced concrete structures under fire.更多还原