附加曲线钢板支撑的预制预应力混凝土装配式梁柱节点抗震性能

Seismic behavior of post-tensioned precast RC beam-column joints with additional curved steel braces

为研究附加曲线钢板支撑的预制预应力混凝土装配式梁柱节点的抗震性能,对不同截面宽度和不同偏心距离的附加曲线钢板支撑的预制预应力混凝土装配式梁柱节点,以及无支撑装配式梁柱节点对比试件进行低周往复荷载试验研究以及数值模拟分析,研究节点试件破坏形式、承载力、刚度、耗能等变化规律。结果表明:在层间位移角不大于5%时,节点试件具有稳定的受力性能,节点梁端混凝土压碎,同时曲线钢板支撑受弯屈服;曲线钢板支撑可提高预应力装配式梁柱节点试件的承载力、刚度和耗能,随着支撑截面宽度的增加以及偏心距离的减小,节点试件承载力、刚度和耗能逐渐提高;在层间位移角为4%时等效黏滞阻尼系数为0.12~0.20,相对无支撑预应力装配节点提高约2~3倍;在曲线钢板支撑偏心率小于0.3时,节点试件承载力受偏心距离影响较大,偏心率大于0.3时,承载力基本不变。

To study the seismic performance of the post-tensioned precast RC beam-column joints with additional curved steel braces,joint specimens braced by curved steel plates with different cross section widths and eccentricities and joint specimens without brace were tested under reversed cyclic loads.The parametric analysis was carried out using the FEA model.The failure mode,bearing capacity,stiffness and energy dissipation,etc.were analyzed.The results show that the whole joints have stable mechanical behavior with inter-story drift angle up to 5%,when concrete crushing at the end of the beam and curved braces yielding under bending.The curved steel brace can improve the bearing capacity,stiffness and energy dissipating capacity of the precast joints.The bearing capacity,stiffness and energy dissipating capacity of joints increase gradually with the increase of brace section width and the decrease of brace eccentricity.The equivalent viscous damping coefficient at inter-story drift angle of 4%is about 0.12 to 0.20,which is two to three times higher than that of the general post-tensioned precast RC joints.When the eccentricity of the curve steel brace is less than 0.3,the resistance of the joint is greatly influenced by the eccentricity.However,the resistance of the joint is slightly influenced by the eccentricity when it is greater than 0.3.