型钢混凝土L形柱空间角节点抗震性能分析

ANALYSIS ON SEISMIC PERFORMANCE OF STEEL REINFORCED CONCRETE L-SHAPED COLUMN SPACE CORNER JOINTS

为研究型钢混凝土L形柱空间角节点的抗震性能,对8个节点试件进行低周反复荷载试验和有限元模拟,二者结果吻合较好。基于此考虑了柱配钢形式、轴压比和加载角度3个变化参数,通过ABAQUS非线性有限元模拟,分析了变化参数对其峰值荷载、耗能和延性的影响规律,并提出可供工程设计参考的建议。研究结果表明,型钢混凝土L形柱空间角节点破坏形态以剪切斜压和弯曲破坏为主,扭转伴随黏结破坏为辅;实腹配钢试件综合抗震性能最好,其峰值荷载较空腹配钢试件提高了10%;随轴压比的增加,不同配钢形式试件的位移延性下降程度不同,实腹配钢试件下降缓慢,建议轴压比限值设计值为0.5;45°加载角度以内,随着加载角度的增加,峰值荷载增加,耗能和延性逐渐降低,45°加载试件与0°平面节点相比,峰值荷载提高了约30%,延性系数降低约10%,最不利加载方向为0°加载。

In order to study the seismic performance of steel reinforced concrete L-shaped column space corner joints, low-cycle reversed loading tests and finite element simulations for 8 specimens were carried out. It indicated that the results of the numerical analysis exhibited a good agreement with those of experiments. While considering three parameters based on the above results, which were the column section steel form, load angle and axial compression ratio, the influences of the three parameters on the seismic performance indicators including the peak load, energy dissipation capacity and displacement ductility were analyzed by using Abaqus nonlinear finite element simulation. Suggestions for engineering design reference were proposed. The results indicated that the failure pattern of steel reinforced concrete L-shaped column space corner joints is dominated by compression-shear and flexural failure, followed by torsion and bond failure. The overall seismic performance of the solid web steel specimen is the best, with its peak load increased by 10% as compared with hollow steel specimens. While increasing the axial compression ratio, the displacement ductility of the specimens with different forms of steel was decreased by different degrees, with solid web steel specimens declining slowly. A value of 0.5 was suggested for the axial compression ratio limit for design. Moreover, when the load angle is less than 45°, the peak load increased while the energy dissipation and ductility decreased gradually with the increase of the load angle. The peak load and the ductility coefficient of the 45° loading specimens were increased by about 30% and decreased by 10% as compared with the 0° loading specimens, which is the most disadvantageous loading direction.