不同火羽流模型下网架结构的抗火分析
发布时间：2018-10-22 09:08
【摘要】：大空间建筑由于特殊的使用功能,屋盖体系常常采用钢结构或组合结构的形式,而钢材较差的耐火性,使得此类建筑结构的抗火设计问题变得尤为突出。而在一般抗火设计中使用的IS0834升温曲线,是一条单调递增的曲线,并不能反应真实的火灾,也并未考虑建筑内可燃物分布、通风条件、烟气辐射等各种影响因素。虽然我国现行《建筑钢结构防火技术规程》中的大空间建筑升温曲线考虑了上述影响因素,但也仅仅是针对轴对称羽流,并未考虑墙角羽流和壁面羽流的情况。本文从上述三种羽流的差异性出发,着重分析三种羽流的温度场分布情况,最后通过一个正放四角锥网架模型说明三种羽流对建筑结构影响,主要的研究内容如下:1.分析了三大经典轴对称羽流的适用范围,在此基础上指出壁面羽流、墙角羽流与轴对称羽流温度场的差异性。然后,通过经典轴对称羽流模型推导出壁面羽流和墙角羽流的温度场简化计算方程,最后利用FDS验证简化方程的正确性。2.结合—正放四角锥网架,利用ANSYS分别计算轴对称羽流、壁面羽流和墙角羽流作用下网架结构的内力分布和位移变化。结果表明,在相同火灾功率下,壁面羽流作用下网架结构的整体位移变化最大,墙角羽流作用下网架结构中各杆件的拉压异号情况最为严重。
[Abstract]:Because of the special function of large space building, the roof system often adopts the form of steel structure or composite structure, but the poor fire resistance of steel makes the fire resistance design problem of this kind of building structure become more and more prominent. However, the IS0834 heating curve used in general fire-resistant design is a monotone increasing curve, which can not reflect the real fire, and does not take into account the distribution of combustible matter in the building, ventilation conditions, smoke radiation and other influencing factors. Although the temperature rise curve of large space buildings in China's current "Building Steel structure Fire Prevention Technical Specification" takes into account the above factors, it is only aimed at axisymmetric plume and does not take into account the case of corner plume and wall plume. Based on the differences of the three plumes mentioned above, the temperature distribution of the three plumes is analyzed in this paper. Finally, the influence of the three plumes on the building structure is explained by a model of the forward quadrangular conical grid. The main research contents are as follows: 1. Based on the analysis of the applicable range of three classical axisymmetric plumes, the differences of the temperature fields of wall plume, corner plume and axisymmetric plume are pointed out. Then, through the classical axisymmetric plume model, the simplified calculation equations of the temperature field of the wall plume and the corner plume are derived. Finally, the correctness of the simplified equation is verified by FDS. 2. The internal force distribution and displacement of the grid structure under the action of axisymmetric plume, wall plume and corner plume are calculated by ANSYS. The results show that under the same fire power, the overall displacement of the grid structure is the largest under the action of wall plume, and the difference between tension and compression of each member of the grid structure is the most serious under the action of corner plume.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU356;TU352.5
本文编号：2286726
[Abstract]:Because of the special function of large space building, the roof system often adopts the form of steel structure or composite structure, but the poor fire resistance of steel makes the fire resistance design problem of this kind of building structure become more and more prominent. However, the IS0834 heating curve used in general fire-resistant design is a monotone increasing curve, which can not reflect the real fire, and does not take into account the distribution of combustible matter in the building, ventilation conditions, smoke radiation and other influencing factors. Although the temperature rise curve of large space buildings in China's current "Building Steel structure Fire Prevention Technical Specification" takes into account the above factors, it is only aimed at axisymmetric plume and does not take into account the case of corner plume and wall plume. Based on the differences of the three plumes mentioned above, the temperature distribution of the three plumes is analyzed in this paper. Finally, the influence of the three plumes on the building structure is explained by a model of the forward quadrangular conical grid. The main research contents are as follows: 1. Based on the analysis of the applicable range of three classical axisymmetric plumes, the differences of the temperature fields of wall plume, corner plume and axisymmetric plume are pointed out. Then, through the classical axisymmetric plume model, the simplified calculation equations of the temperature field of the wall plume and the corner plume are derived. Finally, the correctness of the simplified equation is verified by FDS. 2. The internal force distribution and displacement of the grid structure under the action of axisymmetric plume, wall plume and corner plume are calculated by ANSYS. The results show that under the same fire power, the overall displacement of the grid structure is the largest under the action of wall plume, and the difference between tension and compression of each member of the grid structure is the most serious under the action of corner plume.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU356;TU352.5
【参考文献】
相关期刊论文 前8条
1 薛素铎;梁劲;李雄彦;;大空间建筑火灾空气升温经验公式[J];北京工业大学学报;2013年02期
2 杜咏;李国强;;考虑火焰辐射的大空间建筑火灾中钢构件升温实用计算方法[J];建筑科学与工程学报;2008年03期
3 陈长坤;姚斌;;室内火灾区域模拟烟气羽流模型的适用性[J];燃烧科学与技术;2008年04期
4 白音;石永久;王元清;;门式刚架钢结构火灾下整体力学性能分析[J];北京工业大学学报;2007年05期
5 王文达;韩林海;游经团;;方钢管混凝土柱-钢梁外加强环节点滞回性能的实验研究[J];土木工程学报;2006年09期
6 杜咏;李国强;;基于场模型的大空间建筑火灾钢构件升温的简化计算方法[J];消防科学与技术;2006年03期
7 白音;石永久;王元清;;火灾下大空间结构温度场的数值模拟分析[J];中国安全科学学报;2006年01期
8 丁军,李国强,蒋首超;火灾下钢结构构件的温度分析[J];钢结构;2002年02期
相关博士学位论文 前2条
1 白音;大空间钢结构火灾下受力性能与抗火计算方法研究[D];清华大学;2008年
2 杜咏;大空间建筑网架结构实用抗火设计方法[D];同济大学;2007年
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