【摘要】：鑒于鋼異形柱的承載能力高、截面小、抗震性能好、建筑美觀等優(yōu)點(diǎn)，其應(yīng)用越來(lái)越廣泛，但在火災(zāi)作用下其各項(xiàng)基本力學(xué)性能參數(shù)迅速下降，加之，鋼異形柱是截面不規(guī)則的開(kāi)口薄壁桿件，在火災(zāi)中受火面積大，與型鋼混凝土異形柱相比，耐火性能差。一旦鋼異形柱結(jié)構(gòu)發(fā)生火災(zāi)，極有可能導(dǎo)致整個(gè)結(jié)構(gòu)的坍塌，勢(shì)必造成重大損失，因此對(duì)鋼異形柱抗火性能的研究具有重要的意義。 本文選取典型的T形鋼異形柱作為研究對(duì)象，通過(guò)火災(zāi)試驗(yàn)和ANSYS數(shù)值模擬揭示荷載偏心距以及焊接殘余應(yīng)力對(duì)T形鋼異形柱的影響。具體研究?jī)?nèi)容及成果如下： 1.首先進(jìn)行了5根焊接T形鋼異形柱在SIO0834標(biāo)準(zhǔn)升溫曲線下的火災(zāi)試驗(yàn)。1根T形鋼異形柱施加軸壓荷載，其余4根分別施加不同偏心距的偏心荷載，然后根據(jù)偏心距的變化，分析其臨界溫度、側(cè)向位移、軸向位移、截面溫度場(chǎng)的變化規(guī)律。試驗(yàn)結(jié)果表明：（1）火災(zāi)試驗(yàn)中，各T形鋼異形柱溫度呈不均勻分布，腹板1溫度最高，翼緣3溫度最低，差值約為50℃。（2）無(wú)論偏心距的大小，各T形鋼異形柱的豎向位移隨溫度的變化趨勢(shì)基本一致。（3）無(wú)論偏心距的大小，TZ1—TZ5的破壞形式都屬于彎扭失穩(wěn)。（4）在恒定軸向荷載作用下，隨著偏心距的加大，T形鋼異形柱的臨界溫度不斷降低。（5）在恒定軸向荷載作用下，，T型鋼異形柱隨彎矩的增加，耐火時(shí)間不斷縮短，但其對(duì)耐火時(shí)間的影響逐漸變小。 2.測(cè)量T形鋼異形柱焊接殘余應(yīng)力，分析焊接焊接殘余應(yīng)力在異形柱中的分布規(guī)律，為本文分析焊接殘余應(yīng)力對(duì)T形鋼異形柱抗火性能的影響提供理論基礎(chǔ)和數(shù)據(jù)資料。 3.采用ANSYS有限元分析軟件對(duì)高溫下的T形鋼異形柱的抗火性能進(jìn)行有限元數(shù)值模擬，并與第3章火災(zāi)試驗(yàn)結(jié)果進(jìn)行對(duì)比。根據(jù)偏心距的變化，確定T形鋼異形柱的N-M曲線變化規(guī)律。具體結(jié)論如下：（1）在恒定軸向壓力作用下，T形鋼異形柱的臨界溫度隨偏心距的增大而降低，且T形鋼異形柱的軸向壓力越大，偏心距對(duì)臨界溫度的影響越明顯。（2）當(dāng)為同一臨界溫度時(shí)，T形鋼異形柱的軸向壓力隨著彎矩的增大而降低，基本呈線性遞減趨勢(shì)。（3）當(dāng)臨界溫度不同時(shí)，T形鋼異形柱的軸向壓力隨彎矩增大而降低的速率基本相同。 4.通過(guò)數(shù)值模擬分析殘余應(yīng)力對(duì)T形鋼異形柱抗火性能的影響。具體結(jié)論如下：（1）在相同荷載條件下，有焊接殘余應(yīng)力的異形柱臨界溫度低于無(wú)焊接殘余應(yīng)力異形柱的臨界溫度。（2）當(dāng)T形鋼異形柱荷載比率較小時(shí)，相同條件下，有無(wú)焊接殘余應(yīng)力的臨界溫度差值為20℃-40℃；當(dāng)T形鋼異形柱荷載比率較大時(shí)，相同條件下，有無(wú)焊接殘余應(yīng)力的臨界溫度差值為50℃-150℃。
[Abstract]:In view of the advantages of high bearing capacity, small section, good aseismic performance and beautiful building, the steel special-shaped column has been used more and more widely, but the basic mechanical performance parameters of the steel special-shaped column have declined rapidly under the action of fire, in addition, The steel special-shaped column is a thin-walled member with irregular cross section, which has a large fire area in the fire, and its fire resistance is worse than that of the profiled steel concrete column. Once a fire occurs in a steel special-shaped column structure, it is very likely to cause the collapse of the whole structure, which is bound to cause great losses. Therefore, it is of great significance to study the fire resistance of the steel special-shaped column. In this paper, typical T-shaped steel special-shaped columns are selected as research objects. The effects of load eccentricity and welding residual stress on T-shaped steel special-shaped columns are revealed by fire test and ANSYS numerical simulation. The specific research contents and results are as follows: 1. First, the fire test of 5 welded T-shaped steel special-shaped columns under SIO0834 standard heating curve was carried out. One T-shaped steel special-shaped column was subjected to axial compression load, and the other four were subjected to eccentric load with different eccentricity, and then according to the variation of eccentricity, The variation of critical temperature, lateral displacement, axial displacement and cross-section temperature field is analyzed. The results show that: (1) in the fire test, the temperature of each T-shaped steel special-shaped column is unevenly distributed, the temperature of web 1 is the highest, the temperature of flange 3 is the lowest, and the difference is about 50 鈩

本文編號(hào)：2427103