为了研究地震作用下型钢高强高性能混凝土框架梁的损伤演化过程,对5榀不同含钢率、配箍率下型钢高强高性能混凝土框架梁试件进行了低周反复加载试验。分析了框架梁的破坏形态以及裂缝开展模式,得到了低周反复荷载作用下框架梁的荷载-位移滞回曲线和骨架曲线,研究了不同含钢率、配箍率下框架梁的刚度退化、强度衰减、延性性能、耗能能力等方面的规律与特点。结果表明:在低周反复荷载作用下,经过合理设计的型钢高强高性能混凝土框架梁一般发生弯曲型破坏,且具有良好的延性和抗震耗能能力;随着水平位移幅值和循环次数的增加,框架梁的损伤逐渐累积,使其强度和刚度不断退化,耗能能力降低,但随着含钢率和配箍率的增大,强度和刚度退化幅度减小,累积耗能能力增强。研究结果为进一步建立能够描述型钢高强高性能混凝土框架梁损伤程度的地震损伤模型,揭示损伤对框架梁力学性能的影响提供试验支持。
The process of damage evolution of steel reinforcement high strength high performance concrete(SRHSHPC) frame beams was studied through low cycle reversed loading experiment on 5 frame beam specimens with various steel ratios and stirrups ratios.The crack development and failure model of frame beam specimens were analyzed,while the loading-displacement hysteretic curves and skeleton curves of frame beams were obtained.The law and characteristics of the strength and stiffness degradation,ductility and energy dissipation capacity of frame beams with different steel ratios and stirrups ratios were studied.The result indicates that the SRHSHPC frame beams subjected to low cycle reversed loading produce flexure failure normally by reasonable design,and exhibits good ductility and energy dissipation capacity.As the increase of cycle number and horizontal displacement amplitude,the damage of specimens is accumulated gradually,which causes degradation in strength and stiffness and decrease of energy dissipation capacity.However,the strength and stiffness degradation amplitude are decreased,while the energy dissipation capacity is improved by increasing stirrups ratios and steel ratios.The research will provide experimental support for establishing seismic damage model and further revealing the effect of damage on mechanical property of SRHSHPC frame beams.