T形钢管混凝土压弯构件强度承载性能

Sectional Strength of Concretefilled Tshaped Steel Tube Column Subjected to Axial Compression and Bending Moment

摘要:

采用普通T形钢管混凝土柱的核心混凝土等效单轴本构关系，利用纤维模型程序分析了不同参数对T形钢管混凝土单向压弯、双向压弯柱截面强度的影响，参数包括钢材屈服强度、混凝土抗压强度、管壁宽厚比、截面肢宽厚比、加载角度和轴压比等.研究表明：混凝土工作承担系数和加载角度对归一化的轴力与弯矩相关曲线的形状有重要影响；截面肢宽厚比和轴压比对归一化的双弯矩相关曲线的形状有重要影响.基于截面全塑性假设和大量数值结果回归分析，提出了T形钢管混凝土柱纯弯、单向压弯和双向压弯截面强度承载力的简化计算方法，简化方法计算结果与纤维模型分析结果吻合良好，简化方法可为工程设计提供参考.

Abstract:

In this paper, based on the equivalent uniaxial stressstrain relationship for concretefilled Tshaped steel tube (CFTST) column without stiffening measures, a fiber element model computing program was adopted to investigate the effects of different parameters on the sectional strength of CFTST column under uniaxial eccentric load or biaxial eccentric load. The parameters in the analysis included the yield strength of steel, the compressive strength of concrete, the depth to thickness ratio of steel plate, the depth to width ratio of the sectional limb, the angle of the load and the axial load ratio. The results of theoretical analysis indicated that, the normalized strength interaction curve of axial load versus bending moment was obviously influenced by the load ratio carried by core concrete and the load angle; The normalized strength interaction curve of biaxial bending moments was distinctly influenced by the depth to width ratio of the sectional limb and the axial load ratio. On the assumption of full plastic stress distribution and the parametric regression analyses of a good many of numerical results, the simplified calculation methods were put forward to predict the sectional strength under uniaxial eccentric load or biaxial eccentric load. Good agreements between the values calculated by the simplified calculation methods and the values predicted by the fiber element model computing program were achieved, and the simplified calculation methods can be referred for practical engineering design.