Q690D高强钢焊接截面柱低周反复加载试验研究

Cyclic loading tests of Q690D high strength steel welded columns

为了解强度为Q690D高强度结构钢焊接截面柱的抗震性能,对名义轴压比为0.35的Q690D高强钢焊接H形和箱形截面柱进行了低周反复加载试验。通过观察试件的破坏模式、滞回曲线和骨架曲线,并从其承载能力、塑性发展能力、变形能力和耗能能力等方面对Q690D高强钢柱的滞回性能进行研究。结果表明,试件具有良好的耗能能力和抗震性能;高强钢柱的二阶效应影响不可忽略;反复荷载作用下试件的破坏模式为板件弹塑性局部失稳;试件最大层间位移角分别达到了1/17(H形)和1/23(箱形),远超过GB 50011—2010《建筑抗震设计规范》的层间位移角限值要求;火焰矫正显著影响试件的力学性能和破坏位置,因此对于高强钢试件,应严格控制在受力较大部位采用火焰矫正措施。

To evaluate seismic performance of Q690 D high-strength steel( HHS) welded columns,cyclic loading tests were carried out for H-section and box-section Q690 D HSS welded columns with nominal axial compression ratio of0. 35. Failure modes were observed. The hysteretic loops and skeleton curves of the specimens were obtained. The hysteretic behavior of Q690 D HHS welded columns was further studied from the aspects of bearing capacity,plasticity development,deformation capacity and energy dissipation capacity. According to the test results,Q690 D HHS welded columns show good energy dissipation capacity and seismic performance. Second order effect cannot be neglected for Q690 D HHS welded columns. The failure mode of Q690 D welded column subjected to cyclic loading is elasto-plastic local buckling of plate. The maximum inter-story drift angle reaches 1 /17 for H-section columns and 1 /23 for boxsection columns respectively,which far exceeds the requirement of GB 50011—2010 ‘Code for seismic design of buildings'. Flame straightening significantly affects the mechanical properties of welded box-section HHS columns and then the failure location. Thus it should be strictly restrained from applying flame straightening at the location with high stress ratio for high strength steel member.