实腹式型钢混凝土十形与L形截面柱抗震性能试验及有限元分析

Experimental study and finite element analysis on seismic behavior of solid-web steel reinforced concrete cross-shaped and L-shaped columns

采用"建研式"加载装置对实腹式型钢混凝土十形、L形截面柱各3个试件进行了低周反复加载试验。考虑了配钢率和轴压比的影响,观察了试件的受力过程,分析了破坏形态及荷载-位移滞回曲线和骨架曲线、延性、承载力、刚度、耗能能力等抗震性能指标。基于此,采用ABAQUS并调用纤维模型子程序PQ-Fiber对试验进行有限元模拟,模拟结果与试验结果吻合较好,进而对实腹式型钢混凝土十形和L形截面柱在不同加载角度下的受力性能和轴压比限值进行了分析。结果表明:剪跨比为2.5的实腹式型钢混凝土十形和L形截面柱均呈弯曲型破坏;试件的滞回曲线对称、饱满,延性好,承载力稳定,耗能能力强;十形截面柱沿45°加载时延性最差,沿0°加载时承载力最低; L形截面柱沿45°加载时延性最差,承载力最低。型钢混凝土十形截面柱和L形截面柱二级抗震等级对应的轴压比限值建议分别取0.65和0.45,一级和三级抗震等级时分别减小和增加0.1。

Three solid-web steel reinforced concrete cross-shaped column specimens and three L-shaped column specimens were tested under low cyclic reversed loading using the Kenken-style(PCE)loading device,considering the influence of steel ratio and axial compression ratio.The failure process was observed.The failure patterns and seismic behaviors,such as the load-displacement hysteretic loops and skeleton curves,ductility,strength,stiffness and energy dissipation capacity,were analyzed.Based on the experimental study,finite element analysis(FEA)was carried out using ABAQUS and a subroutine named PQ-Fiber.The FEA results agree well with the experimental results.The influence of loading directions and the limit of axial compression ratio of solid-web steel reinforced concrete cross-shaped columns and L-shaped columns were analyzed.The research results show that the failure pattern of all specimens with a shear span ratio of 2.5 is flexural failure.The hysteretic loops are symmetric and plump.The specimens have good ductility,stable strength and strong capacity of energy dissipation.Solid-web steel reinforced concrete cross-shaped columns have the worst ductility under the loading direction of 45°and the lowest bearing capacity under the loading direction of 0°.Solid-web steel reinforced concrete L-shaped columns have the worst ductility and the lowest bearing capacity under the loading direction of 45°.The limits of axial compression ratio of solid-web steel reinforced concrete cross-shaped and L-shaped columns corresponding to the second grade of seismic requirements are 0.65 and 0.45,respectively.For both types of columns,the limit decreases by 0.1 for the first grade of seismic requirements and increases by 0.1 for the third grade of seismic requirements.