轴压比对SRC-RC转换柱抗震性能影响的试验研究

轴压力是影响构件抗震性能的主要因素之一,通过14根型钢混凝土-钢筋混凝土(steel reinforced concrete-reinforced concrete,SRC-RC)转换柱试件的低周反复荷载试验分析了轴压比对试件基本力学行为的影响.虽然较大的轴压力能提高试件在反复荷载下的承载能力和初始侧移刚度,但同时降低了试件的极限变形能力.轴压比较大试件的滞回环面积较小,耗能能力较差.对于型钢延伸高度较大的试件,较大的轴压力使强度衰减现象在加载后期越来越显著,承载力的稳定性在较短的时间内丧失.较大的轴压力导致试件的位移延性系数减小、屈服后变形能力降低.轴压比对位移延性的影响与试件的构造特征存在耦合关系.

Effect of Axial Compressive Ratio on Seismic Behavior of SRC-RC Transfer Columns

Axial compressive ratio has significant effects on seismic performance of steel reinforced concrete-reinforced concrete(SRC-RC) transfer columns.Experiments of 14 transfer columns under low cyclic shear were carried out to analyze the mechanical behavior of SRC-RC transfer columns with different axial compression.Axial compressive force can not only promote the strength under cyclic shear and stiffness at initial stage but also diminish the rotated ability of cross section and ultimate deformation ability of specimens.High axial compressive ratio makes the area of hysteretic loops decrease and energy dissipation ability weakness.For the specimens with long extension length of shape steel,strength degenerate rapidly specially at last period of loading,and the stability of strength loses soon.Increment of axial compressive ratio also leads to the drop down of displacement ductility and postpeak behavior.The variation of displacement ductility with axial compressive ratio has relationship with the configuration and steel arrangement of specimens.