【作者】 黄宏；

【导师】 韩林海； 陶忠；

【作者基本信息】 福州大学 ， 结构工程， 2006， 博士

【摘要】 本文从理论和试验两个方面较系统地研究了圆、方中空夹层钢管混凝土构件在单调加载(包括轴压、纯弯、压弯荷载)下的力学性能和工作机理,以及其在往复荷载作用下的滞回性能,并在参数分析的基础上,提出了圆、方中空夹层钢管混凝土轴压、纯弯和压弯构件承载力的实用计算方法和弯矩-曲率、荷载-位移滞回关系模型及延性系数的确定方法。本文具体进行了以下几个方面的工作:(1)分别以径厚比、空心率、长细比、偏心距等为主要变化参数,较系统地进行了轴压、纯弯和压弯构件在单调加载下的试验研究。(2)用纤维模型和ABAQUS有限元软件建模两种方法对轴压、纯弯和压弯构件的荷载-变形全过程进行计算,计算结果均得到试验结果的验证。在此基础上,用ABAQUS建模对轴压、纯弯和压弯构件受力全过程中内外钢管与混凝土的应力分布、三者之间的相互作用以及内外钢管的破坏形态进行了研究。分析了空心率对轴压、纯弯和压弯构件力学性能的影响,讨论了加载路径对压弯构件承载力的影响。用纤维模型法系统地分析了截面含钢率、空心率、钢材和混凝土强度等因素对构件承载力的影响,提出了轴压、纯弯和压弯构件承载力的实用计算方法。(3)以空心率和轴压比为主要变化参数,进行了压弯构件在往复荷载作用下的试验研究。(4)利用纤维模型法,对压弯构件的M-φ和P-Δ滞回关系曲线及其骨架线进行了分析。利用ABAQUS建模对构件的荷载-位移骨架曲线进行了计算,两种计算方法都得到了试验结果的验证。用纤维模型法系统地分析了轴压比、长细比、截面含钢率、钢材和混凝土强度等参数对M-φ和P-Δ滞回曲线骨架线的影响规律,提出了压弯构件M-φ、P-Δ滞回关系模型及延性系数的确定方法。更多还原

【Abstract】 Behavior and mechanism of Concrete filled double-skin steel tubular (CFDST) beam-columns subjected to monotonic or cyclic loading were investigated. Two kinds of CFDST section tubes were studied in this paper, that is, the outer steel tubes are circular hollow sections (CHS) or square hollow sections (SHS), while all the inner steel tubes are CHS. Based on systematic parameter analysis, simplified models were derived to predict the load-carrying capacities of the composite members, and simplified moment-curvature and lateral load-lateral deflection hysteretic models, as well as ductility coefficient were suggested.The main achievements were summarized in detail as follows:(1) The CFDST tubular beams, columns and beam-columns with CHS outer steel tubes were tested systematically. The main experimental parameters were tube diameter-to-thickness ratio, hollow section ratio, eccentricity and slenderness ratio.(2) Load-deformation relationship curves of CFDST subjected to compression and bending were analyzed by finite element method and fiber element method. The predicted load versus deformation relationship curves are in good agreement with those of tests. Stress distributions of steel and concrete, interactions between steel and concrete and failure modes of inner and outer steel tubes were analyzed by finite element method. The influences of hollow section ratio on the mechanism of CFDST beams, columns and beam-columns were analyzed. The influences of different loading paths on the bearing capacities of the CFDST beam-columns were also discussed. Parametric analysis was performed on the influences of bearing capacities of the composite members by fiber element method. The selected parameters were hollow section ratio, steel ratio, strength of the materials, etc. Simplified models were derived for the member capacities of the composite beam-columns.(3) The CFDST beam-columns were tested under constant compressive axial load and cyclic lateral load. The main parameters varied in the tests are axial load ratio and hollow section ratio.(4) Moment-curvature hysteretic curves, load-displacement hysteretic curves and their skeleton curves were calculated by fiber element method. Moment-curvature relationship skeleton curves and load-displacement relationship skeleton curves were also calculated by finite element method. The predicted curves are in good agreement with those of tests. Based on the fiber element method, parametric analysis was performed on the behaviors of moment-curvature and lateral load-lateral displacement relationships for the composite beam-columns. The selected parameters were the axial load level, slenderness ratio, steel ratio, strength of the materials, etc. Finally, simplified models for the moment-curvature and the lateral load-lateral displacement hysteretic relationships, as well as simplified formula for calculating ductility coefficient were suggested.更多还原