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（1 蘇州科技大學土木工程學院， 蘇州 215011； 2 東南大學交通學院， 南京 210096)
［摘要］梁桁體系組合梁是一種新型鋼-混凝土組合結(jié)構(gòu)，通過對其結(jié)構(gòu)的靜力試驗研究，分析了其沿截面高度縱向應(yīng)變、混凝土翼板縱向應(yīng)變、鋼梁腹板應(yīng)變、腹桿軸向應(yīng)變隨荷載的發(fā)展變化及跨中截面撓度變化規(guī)律和破壞機理。試驗結(jié)果表明：組合梁從開始受荷到最終破壞整個過程經(jīng)歷彈性、彈塑性及破壞3個受力階段，其破壞模式為典型的彎曲破壞；混凝土頂板剪力滯效應(yīng)較明顯，沿截面高度縱向應(yīng)變發(fā)展仍符合平截面假定，在純彎段內(nèi)中和軸有明顯上移趨勢，桁架腹桿為壓彎桿件或拉彎桿件；屈服荷載時撓跨比為1/418，極限荷載時撓跨比達到1/54，整體上體現(xiàn)出其具有良好的變形和延性能力。采用ABAQUS軟件對與試驗梁同尺寸的模型進行有限元分析，驗證了試驗結(jié)果的正確性及有限元模型的合理性；對比分析無傾斜桁架的同尺寸模型，得到梁桁體系組合梁極限承載力相對于無傾斜桁架組合梁提高了20%左右。
［關(guān)鍵詞］組合梁； 梁桁體系； 靜力性能； 試驗研究； 有限元分析
中圖分類號：TU398+.6文獻標識碼：A文章編號：1002-848X(2016)22-0092-07
Experimental study and finite element analysis on static behavior of composite beam with hybrid full web and truss system
Chen Jianbing1， Li Xiayuan2
(1 School of Civil Engineering, Suzhou University of Science and Technology, Suzhou 215011, China;2 School of Transportation, Southeast University, Nanjing 210096, China)
Abstract:The composite beam with hybrid full web and truss system is a new type of steel-concrete composite structure. Through the static experimental study on the structure, the developments of the longitudinal strain along section height, longitudinal strain of concrete flange plate, steel beam web plate strain, web member axial strain with the change of the load were analyzed. And the deflection change as well as failure mechanism of mid-span section were analyzed. The experimental results reveal that the composite beam experiences three different mechanical stages in the whole process from initial loading to final failure, including elastic stage, elastic-plastic stage and failure stage. The beam features the typical flexural failure mode. The shear-lag effect on concrete roof plate is obvious, and the longitudinal strain distribution along the depth of cross-section obeys the plain section assumption. The neutral axis in the pure bending section has a significant upper shift tendency, and the web member of truss is compression bending bar or stretch bending bar. The ratio of the deflection to span is 1/418 while achieving yield load, and this ratio is 1/54 while reaching the ultimate load. The overall structure performs well in deformation and ductility. The beam model with identical size of the test beam was built based on ABAQUS nonlinear finite element software to prove the correctness of experimental results and the reasonability of finite element model. The aclinic truss model with the same size of the test one was analyzed and compared with the model to conclude that the ultimate bearing capacity of composite beam with hybrid full web and truss system increases by about 20% compared with composite beam with aclinic truss.
Keywords:composite beam; hybrid full web and truss system; static behavior; experimental study; finite element analysis
*江蘇省結(jié)構(gòu)工程重點實驗室基金項目（ZD1102）。
作者簡介：陳建兵，教授，Email：szctt2009@163.com。
