方钢管混凝土压弯构件截面非线性分析

构件截面非线性分析是进行结构抗震性能分析的重要基础,针对方钢管混凝土构件中钢管的三向受力特点,提出了一种适于计算方钢管混凝土压弯构件弯矩-曲率骨架曲线的钢材本构模型,模型中考虑了钢材的环向拉力作用;并应用提出的钢材模型和已有的混凝土模型编制了纤维模型数值计算程序;分析了含钢率、轴压比、混凝土强度和钢材强度对方钢管混凝土压弯构件截面弯矩-曲率曲线的影响。通过对构件屈服弯矩、极限弯矩的分析,提出了一种方钢管混凝土压弯构件的三线性骨架曲线,该曲线可用于工程中方钢管混凝土框架结构的动力学分析。

NONLINEAR ANALYSIS OF CONCRETE-FILLED SQUARE STEEL TUBULAR BEAM-COLUMN SECTIONS UNDER BENDING AND AXIAL LOAD

Nonlinear analysis of member sections play an important role in structural seismic investigation.Based on the triaxial-force feature of the steel,a constitutive model of steel suitable for concrete-filled square steel tubular beam-column was proposed for establishing moment-curvature envelop curve,meanwhile hoop tension stress was considered in this model;a fiber-based numerical model program for beam-columns subjected to bending and axial load was developed with the proposed steel constitutive model and the existing confined concrete constitutive model.The influence on moment-curvature envelop curve of concrete-filled square steel tubular beam-column from those parameters,including steel ratio,steel yield strength,concrete strength and axial compression ratio,was studied respectively.The trilinear envelop curve model of concrete-filled square steel tubular beam-column was proposed by the analysis of yield moment and ultimate bending moment,and this model could be used for the structural dynamic analysis of projects.