不同加载方式下实腹式型钢混凝土T形截面柱损伤试验研究

Experimental investigation on damage of solid-web steel reinforced concrete T-shaped columns under different loading patterns

为研究不同加载方式下实腹式型钢混凝土T形截面柱沿腹板方向的损伤演化规律,设计并制作了10根缩尺比为1/2、剪跨比为2.5的型钢混凝土T形截面柱,变化参数为轴压比、配钢率及加载制度。基于试验成果,对单调荷载及低周反复荷载作用下T形截面柱的荷载-位移曲线及能量耗散能力进行了分析。结果表明:从初始加载到失效,型钢混凝土T形截面柱的损伤过程可分为5个阶段,分别为无损阶段、轻微损伤阶段、损伤稳步发展阶段、严重损伤阶段和破坏阶段;与单调加载相比,随着位移幅值的增大与荷载循环次数的增加,T形截面柱的承载力、极限变形能力和极限耗能能力均有不同程度的降低。在试验研究的基础上,考虑荷载循环次数、位移幅值与极限承载能力的动态关系以及加载路径对T形截面柱损伤的影响,建立了由最大变形与滞回耗能双参数组合的非线性损伤模型,并验证了该模型的合理性。

In order to research the damage evolution rules of solid-web steel reinforced concrete T-shaped columns along the direction of web under different loading patterns,ten specimens with a scaling ratio of 1 /2 and a shear span ratio of 2. 5 were designed by changing the parameters of axial compression ratio,steel ratio and loading patterns.Load-displacement curves and hysteretic energy were analyzed under monotonic loading or low cyclic reversed loading.The results show that the damage process of specimens can be divided into five stages,namely the undamaged stage,slightly damaged stage,stably damaged stage,seriously damaged stage and totally damaged stage. With the increase of displacement amplitude and loading cycles, the bearing capacity, ultimate deformation capacity, and energy dissipation capacity are decreased in various degrees. Based on the experimental study,a nonlinear damage model combined with the maximum deformation and hysteretic energy dissipation was established by considering the dynamic relationship between cycle number,displacement amplitude and ultimate bearing capacity and the influence of loading paths on damage development,meanwhile the rationality of the model was verified.