带直角六边形钢管混凝土柱的滞回性能研究

The Hysteretic Behavior of Concrete-Filled Hexagonal Steel Tubular Columns with Right Angle

带直角六边形钢管混凝土柱具有表面平整和抗震性能好的优点,已被应用于实际工程中。为进行该类结构的非线性抗震分析,基于有限元法研究了其滞回性能,并开展了参数分析,主要参数包括:含钢率、混凝土强度、钢材强度、轴压比和长细比。分析结果表明:该类组合构件的承载力随着含钢率和钢材强度的增大而提高,随着长细比和轴压比的增大而降低;抗弯刚度随着含钢率的增大而增大,随着长细比的增大而减小;长细比和轴压比对骨架曲线形状的影响较大;骨架曲线下降段刚度随着轴压比和混凝土强度的增大而增大,随着长细比的增大而减小;构件绕强轴破坏时具有更好的延性。最后给出了该类构件的荷载-位移恢复力建议模型,简化计算结果和试验结果吻合较好。

The concrete-filled hexagonal steel tubular(CFHST) column with right angle has many advantages such as smooth surface and good seismic performance.It has been used in many real projects.In order to carry out nonlinear seismic analysis of this structure, the hysteretic properties of the CFHST column with right angle are studied in this paper using finite element method, and the parametric analysis is conducted.The main parameters include steel ratio, concrete strength, steel strength, axial compression ratio and slenderness ratio.The analysis results show that the bearing capacity of the composite specimen increases with the increase of steel ratio and steel yield strength, and decreases with the increase of slenderness ratio and axial compression ratio.The flexural rigidity of the composite specimen increases with the increase of steel ratio, and decreases with the increase of slenderness ratio.The slenderness ratio and axial compression ratio have significant influence on the shape of skeleton curve.The stiffness of the descending stage of the skeleton curve increases with the increase of axial compression ratio and concrete strength, and it decreases as the slenderness ratio increases.The specimen bending around the strong axis exhibits a better ductility.Finally, the load-displacement restoring force model of the CFHST column is proposed.The simplified calculation results are in a good agreement with experimental results.