發(fā)布時間：2018-10-22 09:08

【摘要】：大空間建筑由于特殊的使用功能,屋蓋體系常常采用鋼結(jié)構(gòu)或組合結(jié)構(gòu)的形式,而鋼材較差的耐火性,使得此類建筑結(jié)構(gòu)的抗火設(shè)計問題變得尤為突出。而在一般抗火設(shè)計中使用的IS0834升溫曲線,是一條單調(diào)遞增的曲線,并不能反應(yīng)真實(shí)的火災(zāi),也并未考慮建筑內(nèi)可燃物分布、通風(fēng)條件、煙氣輻射等各種影響因素。雖然我國現(xiàn)行《建筑鋼結(jié)構(gòu)防火技術(shù)規(guī)程》中的大空間建筑升溫曲線考慮了上述影響因素,但也僅僅是針對軸對稱羽流,并未考慮墻角羽流和壁面羽流的情況。本文從上述三種羽流的差異性出發(fā),著重分析三種羽流的溫度場分布情況,最后通過一個正放四角錐網(wǎng)架模型說明三種羽流對建筑結(jié)構(gòu)影響,主要的研究內(nèi)容如下:1.分析了三大經(jīng)典軸對稱羽流的適用范圍,在此基礎(chǔ)上指出壁面羽流、墻角羽流與軸對稱羽流溫度場的差異性。然后,通過經(jīng)典軸對稱羽流模型推導(dǎo)出壁面羽流和墻角羽流的溫度場簡化計算方程,最后利用FDS驗證簡化方程的正確性。2.結(jié)合—正放四角錐網(wǎng)架,利用ANSYS分別計算軸對稱羽流、壁面羽流和墻角羽流作用下網(wǎng)架結(jié)構(gòu)的內(nèi)力分布和位移變化。結(jié)果表明,在相同火災(zāi)功率下,壁面羽流作用下網(wǎng)架結(jié)構(gòu)的整體位移變化最大,墻角羽流作用下網(wǎng)架結(jié)構(gòu)中各桿件的拉壓異號情況最為嚴(yán)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.
【學(xué)位授予單位】：昆明理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TU356;TU352.5

【參考文獻(xiàn)】

相關(guān)期刊論文 前8條

1 薛素鐸;梁勁;李雄彥;;大空間建筑火災(zāi)空氣升溫經(jīng)驗公式[J];北京工業(yè)大學(xué)學(xué)報;2013年02期

2 杜詠;李國強(qiáng);;考慮火焰輻射的大空間建筑火災(zāi)中鋼構(gòu)件升溫實(shí)用計算方法[J];建筑科學(xué)與工程學(xué)報;2008年03期

3 陳長坤;姚斌;;室內(nèi)火災(zāi)區(qū)域模擬煙氣羽流模型的適用性[J];燃燒科學(xué)與技術(shù);2008年04期

4 白音;石永久;王元清;;門式剛架鋼結(jié)構(gòu)火災(zāi)下整體力學(xué)性能分析[J];北京工業(yè)大學(xué)學(xué)報;2007年05期

5 王文達(dá);韓林海;游經(jīng)團(tuán);;方鋼管混凝土柱-鋼梁外加強(qiáng)環(huán)節(jié)點(diǎn)滯回性能的實(shí)驗研究[J];土木工程學(xué)報;2006年09期

6 杜詠;李國強(qiáng);;基于場模型的大空間建筑火災(zāi)鋼構(gòu)件升溫的簡化計算方法[J];消防科學(xué)與技術(shù);2006年03期

7 白音;石永久;王元清;;火災(zāi)下大空間結(jié)構(gòu)溫度場的數(shù)值模擬分析[J];中國安全科學(xué)學(xué)報;2006年01期

8 丁軍,李國強(qiáng),蔣首超;火災(zāi)下鋼結(jié)構(gòu)構(gòu)件的溫度分析[J];鋼結(jié)構(gòu);2002年02期

相關(guān)博士學(xué)位論文 前2條

1 白音;大空間鋼結(jié)構(gòu)火災(zāi)下受力性能與抗火計算方法研究[D];清華大學(xué);2008年

2 杜詠;大空間建筑網(wǎng)架結(jié)構(gòu)實(shí)用抗火設(shè)計方法[D];同濟(jì)大學(xué);2007年

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