低屈强比高强钢箱形柱抗震性能试验研究

钢结构的材料高强化是发展趋势，目前高强钢存在屈强比过高的问题，限制了高强钢在建筑结构中的抗震设计应用。对低合金高强度结构钢进行材性改良，研发出一种新型低屈强比Q620E高强钢。对此新型高强钢的抗震性能进行试验研究，根据壁板宽厚比等级设计截面尺寸不同的箱形截面柱，对轴压比为0.2和0.35的高强钢箱形柱进行低周往复加载试验。通过观察试件的破坏模式、提取滞回曲线和骨架曲线，从承载力、延性、耗能性能与损伤发展等方面对钢柱的抗震性能进行分析，并与Q690D普通高强钢柱抗震性能进行比较。试验结果表明，低屈强比高强钢柱具有良好的滞回性能和塑性变形能力；壁板宽厚比对构件承载力及延性影响显著；壁板宽厚比越大则刚度下降越快、损伤发展不连续；相较于Q690D普通高强钢，Q620E新型钢在力学性能与构件抗震方面均体现出较大的优势，可考虑在高强钢建筑结构中拓展应用。

Experimental analysis on seismic behavior of low yield ratio high strength steel box-section column

The high strength of steel structure is the main trend. At present, the high yield ratio is the problem of the high strength steel, which limits the application of high strength steel in the seismic design of structures. A new type of high strength steel with a low yield ratio Q620E has been developed in HBIS Group by improving the material properties of low alloy high strength structural steel. In order to study the seismic performance of it, box-section columns with different cross-sectional dimensions were designed according to classes width-to-thickness ratio of steel columns. Low-cycle reversal tests were performed on box-shaped columns of high strength steel with nominal axial compression ratios of 0.2 and 0.35. The seismic performance of steel columns was investigated in terms of bearing capacity, ductility, energy dissipation performance and damage index by observing the damage modes, extracting hysteresis curves and skeleton curves of the specimens and comparing the seismic performance with that of Q690D ordinary high-strength steel columns. The test results show that the designed high-strength steel columns have good hysteresis performance and plastic deformation capacity; width-to-thickness ratio has a significant effect on the bearing capacity and ductility of the members; the larger width-to-thickness ratio is, the faster the stiffness dissipation capacity of the member decreases and discontinuous damage development occurs; compared with Q690D ordinary high-strength steel, Q620E steel shows greater advantages in mechanical properties and seismic design of the member, which can be considered for high-strength steel structures.