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(1 天津大學(xué)建筑工程學(xué)院， 天津 300072；2 天津大學(xué)濱海土木工程結(jié)構(gòu)與安全教育部重點(diǎn)實(shí)驗(yàn)室， 天津 300072)

［摘要］為研究梁柱節(jié)點(diǎn)轉(zhuǎn)動(dòng)剛度對(duì)結(jié)構(gòu)抗連續(xù)倒塌性能的影響，建立平面鋼框架模型，并在模型中加入轉(zhuǎn)動(dòng)彈簧以模擬節(jié)點(diǎn)轉(zhuǎn)動(dòng)剛度。分別對(duì)不考慮節(jié)點(diǎn)剛度退化的剛接和線性節(jié)點(diǎn)模型以及考慮節(jié)點(diǎn)剛度退化的非線性節(jié)點(diǎn)模型進(jìn)行數(shù)值分析。結(jié)果表明：考慮節(jié)點(diǎn)剛度退化會(huì)使動(dòng)力放大系數(shù)增大；結(jié)構(gòu)在彈性狀態(tài)下，動(dòng)力放大系數(shù)維持在2-0左右，不考慮節(jié)點(diǎn)剛度退化模型可用于連續(xù)倒塌分析；結(jié)構(gòu)在塑性狀態(tài)下，動(dòng)力放大系數(shù)隨節(jié)點(diǎn)轉(zhuǎn)動(dòng)剛度與需求能力比（DCR）的增大而減小，不考慮節(jié)點(diǎn)剛度退化模型不宜用于連續(xù)倒塌分析；隨著節(jié)點(diǎn)轉(zhuǎn)動(dòng)剛度的增大，節(jié)點(diǎn)耗能占結(jié)構(gòu)總耗能比例減小，梁耗能比例增加。因此建議當(dāng)節(jié)點(diǎn)轉(zhuǎn)動(dòng)剛度較小時(shí)增加節(jié)點(diǎn)的變形能力以提高結(jié)構(gòu)的抗連續(xù)倒塌性能，反之增加梁的變形能力。

［關(guān)鍵詞］節(jié)點(diǎn)轉(zhuǎn)動(dòng)剛度；  連續(xù)倒塌； 鋼框架； 動(dòng)力放大系數(shù)； 耗能

中圖分類號(hào)：TU391文獻(xiàn)標(biāo)識(shí)碼：A文章編號(hào)：1002-848X(2017)16-0009-05

Research on progressive collapse resistance performance of steel frame considering beam-to-column joint rotational stiffness

Liu Shipeng1， Liu Mingjie1， Lu Yan1,2， Zhao Yifeng1

（1 School of Civil Engineering， Tianjin University， Tianjin 300072，  China；   2 Key Laboratory of Coast Civil Structure Safety, Ministry of Education, Tianjin University, Tianjin 300072, China）

Abstract:The plane steel frame model was established to study the influence of beam-to-column joint rotational stiffness on the structural progressive collapse resistance performance. The rotational spring element was used in the model to simulate joint rotational stiffness. Numerical analyses were made on the rigid model and linear joint model without considering joint stiffness degradation and the nonlinear joint model considering joint stiffness degradation. The analytical results show that the dynamic magnification factor increases if joint stiffness degradation is considered. The dynamic magnification factor remains at about 2-0 and the model without considering joint stiffness degradation can be adopted for the progressive collapse analysis when the structure is in the elastic state. The dynamic magnification factor decreases with the increase of rotational stiffness and Demand-Capacity Ratio (DCR)  and the model  without considering joint stiffness degradation can not be adopted for the progressive collapse analysis during the plastic state. With the increase of joint rotational stiffness, the ratio of joint energy dissipation to total energy dissipation is decreased, while that of beam is increased. Therefore, it is suggested that the joint deformation ability should be reinforced to improve the structural progressive collapse resistance performance when joint rotational stiffness is decreased, otherwise the beam deformation ability should be reinforced.

Keywords:joint rotational stiffness; progressive collapse; steel frame; dynamic magnification factor; energy dissipation

*天津市城鄉(xiāng)建設(shè)和交通委員會(huì)建設(shè)科技項(xiàng)目（2013-35），國(guó)家自然科學(xué)基金面上項(xiàng)目（51178307）。

通訊作者：蘆燕，博士，講師，Email: yanlu86@tju.edu.cn。