本文關(guān)鍵詞： 鋼管桁架 穩(wěn)態(tài)試驗 瞬態(tài)試驗 性能化設(shè)計 火災(zāi)分析　出處：《中國礦業(yè)大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：鋼管桁架結(jié)構(gòu)在結(jié)構(gòu)形式與經(jīng)濟效益上具有明顯優(yōu)勢,進行鋼管桁架結(jié)構(gòu)的火災(zāi)響應(yīng)分析,是完善大空間鋼結(jié)構(gòu)抗火研究非常必要的一部分。本文以某會展中心為工程背景,對鋼管桁架結(jié)構(gòu)的火災(zāi)響應(yīng)進行了研究,主要內(nèi)容如下:分別采用穩(wěn)態(tài)與瞬態(tài)兩種試驗方法對Q345管材進行了高溫試驗研究,試驗結(jié)果表明各項力學(xué)性能由試驗方法造成的差異非常明顯。故基于瞬態(tài)試驗提出了Q345鋼管熱膨脹系數(shù)、高溫屈服強度與高溫彈性模量的計算模型,并與國內(nèi)外幾種經(jīng)典模型進行了對比,驗證了其正確性與可行性。以某會展中心為工程背景,基于性能化的防火設(shè)計方法,制定了結(jié)構(gòu)的防火安全目標(biāo),并對火災(zāi)的危險性、火災(zāi)荷載、火源位置、消防系統(tǒng)的有效性等各方面進行分析,從而確定了四種最不利的火災(zāi)場景。分析表明,采用ISO標(biāo)準(zhǔn)升溫曲線與高大空間建筑火災(zāi)空氣升溫實用曲線進行大空間建筑溫度場的模擬是不準(zhǔn)確、不適用的。因此,本文以某會展中心工程為背景,利用FDS軟件分析了大空間建筑溫度場的分布規(guī)律。分析結(jié)果表明各火災(zāi)場景下溫度場均呈現(xiàn)明顯不均勻分布,且火源位置與火源面積對結(jié)構(gòu)的升溫都有一定的影響。并根據(jù)火災(zāi)下鋼構(gòu)件升溫的實用計算方法,利用MATLAB軟件計算了各構(gòu)件的升溫曲線,四種火災(zāi)場景下,構(gòu)件溫度最高可達(dá)334.41℃、292.60℃、240.24℃及211.26℃。利用ANSYS軟件模擬了不同火災(zāi)場景下,結(jié)構(gòu)整體的火災(zāi)響應(yīng)規(guī)律與局部降溫后結(jié)構(gòu)的力學(xué)性能變化。模擬結(jié)果表明,鋼管桁架結(jié)構(gòu)在設(shè)計時,應(yīng)適當(dāng)增大支座附近弦桿截面積,減小外挑尺寸,在使用及維護過程中,盡量避免在屋蓋支座附近堆積可燃物,可燃物面積不可過大,且較高展位應(yīng)布置在凈空較高區(qū)域。且對鋼結(jié)構(gòu)進行滅火時,應(yīng)盡量避免在火災(zāi)全盛期對高溫桿件直接進行噴水冷卻。研究結(jié)果可為鋼管桁架結(jié)構(gòu)性能化防火設(shè)計與安全評估提供參考。
[Abstract]:The steel tube truss structure has obvious advantages in structure form and economic benefit. The fire response analysis of steel tube truss structure is a necessary part of improving the fire resistance of large space steel structure. In this paper, a conference and exhibition center is taken as the engineering background. The fire response of steel tube truss structure is studied. The main contents are as follows: the high temperature test of Q345 tube is carried out by using steady and transient test methods. The test results show that the difference of mechanical properties caused by the test method is very obvious. Therefore, based on the transient test, the calculation model of thermal expansion coefficient, high temperature yield strength and high temperature elastic modulus of Q345 steel pipe is proposed. Compared with several classical models at home and abroad, the correctness and feasibility of the model are verified. Taking a certain exhibition center as the engineering background, based on the performance-based fire prevention design method, the fire safety target of the structure is established, and the fire risk is also discussed. The fire load, the location of the fire source and the effectiveness of the fire control system are analyzed to determine the four most unfavorable fire scenarios. It is not accurate and applicable to simulate the temperature field of large space building by using ISO standard heating curve and practical curve of air heating in large space building fire. Therefore, this paper takes a conference and exhibition center project as the background. The distribution of temperature field in large space building is analyzed by using FDS software. The results show that the temperature field of large space buildings is distributed unevenly in every fire scene. And the location of fire source and the area of fire source have certain influence on the heating of structure. According to the practical calculation method of heating up of steel component under fire, the heating curve of each component is calculated by using MATLAB software. The maximum component temperature can reach 334.41 鈩，

本文編號：1513982