884aa四虎影成人精品,99久久国产综合精品女图图等你,97在线观看永久免费视频,久久精品国产精品亚洲38,ⅵdeodesetv性欧美

(1 天津大學(xué)水利工程仿真與安全國(guó)家重點(diǎn)實(shí)驗(yàn)室， 天津 300072；  2 天津大學(xué)建筑工程學(xué)院，天津 300072；  3 天津大學(xué)建筑學(xué)院， 天津 300072； 4 大元建業(yè)集團(tuán)股份有限公司， 滄州 061000)

［摘要］對(duì)蒸壓輕質(zhì)加氣混凝土板（ALC板）處理過(guò)的L形方鋼管混凝土組合異形柱（SCFST柱）進(jìn)行了3h耐火試驗(yàn)，結(jié)果表明該柱滿(mǎn)足一級(jí)耐火等級(jí)柱構(gòu)件的耐火極限要求。為了研究其受火后力學(xué)性能，對(duì)柱進(jìn)行了軸壓試驗(yàn)，得到其荷載-位移曲線、荷載-撓度曲線和荷載-應(yīng)變曲線。通過(guò)分析試驗(yàn)曲線和現(xiàn)象發(fā)現(xiàn)，加載初期L形SCFST柱表現(xiàn)出良好的線彈性，達(dá)到極限承載力之后，柱表現(xiàn)出較好的延性，三肢單柱間協(xié)同作用良好。L形SCFST柱繞弱軸XX發(fā)生整體彎曲，最終由于固定端的混凝土被壓碎和鋼管鼓曲開(kāi)裂導(dǎo)致承載力喪失。通過(guò)有限元模擬得到SCFST柱的極限承載力和破壞模態(tài)，以及采用疊加理論得到SCFST柱的極限承載力，均與試驗(yàn)結(jié)果基本吻合，證明了這兩種方法的可行性。對(duì)比結(jié)果表明受火后SCFST柱的材料性能和結(jié)構(gòu)構(gòu)造并未受到明顯的影響，仍具有較高的承載力，進(jìn)而驗(yàn)證了SCFST柱采用ALC板作為防火處理措施的可行性。

［關(guān)鍵詞］鋼管混凝土； 異形柱； 受火后承載力； 軸壓試驗(yàn)； 有限元； 疊加理論

中圖分類(lèi)號(hào)：TU323-1文獻(xiàn)標(biāo)識(shí)碼：A文章編號(hào)：1002-848X(2019)14-0029-07

Experimental study of axial compression bearing capacity for full-size L special-shaped column composed of concrete-filled square steel tubes after fire

Chen Zhihua1,2, Lei Zhiyong2, Zhao Bingzhen2, Zhou Ting3, Yang Xiangdong4, Xiong Zhenzhen4

(1 Key State Laboratory of Hydraulic Engineering Simulation and Safety of Tianjin University, Tianjin 300072, China; 2 School of Civil Engineering, Tianjin University, Tianjin 300072, China; 3 School of Architecture, Tianjin University, Tianjin 300072, China;  4 Dayuan Group Company, Cangzhou 061000, China)

Abstract:The fire resistance test for L special-shaped column composed of concrete-filled square steel tubes (SCFST column) covered by autoclaved lightweight concrete (ALC board) was carried out. The results show that the column meets the requirements of the specification for the first grade refractory component. In order to analyze its mechanical properties after fire, axial compression test of the column was carried out, obtaining the load-displacement curve, load-deflection curve and load-strain curve. By analyzing the curves and experimental phenomena, L shaped SCFST column showed good linear elasticity in the loading initial stage. After reaching the ultimate bearing capacity, the column performed fine ductility and the three mono-columns showed good synergy work. The overall bending of L shaped SCFST column around the weak axial XX column was found. Finally, the crush of concrete and buckle-creak of steel tubes at the fixed end leaded to the loss of bearing capacity. The ultimate bearing capacity and failure mode of SCFST columns getting form finite element analysis and the ultimate bearing capacity obtained by superposition theory were basically identical to the results of test, showing that those two methods are feasible. The comparison results show that the material property and detail structure of SCFST column were not obviously affected by the fire and the SCFST column still has high bearing capacity, proving that it is feasible to use ALC board as fire precaution measure for SCFST column.

Keywords:concrete-filled steel tube; special-shaped column; bearing capacity after fire; axial compression test; finite element analysis; superposition theory