Q690钢柱静力承载与抗震设计方法研究

Compared with conventional mild carbon steel, the application of high strength structural steel could not only reduce the total steel consumption, but also can provide rational structural design for landmark buildings and complicated structures. Recently, grades of Q460~Q960 steel have been developed by steel and iron companies in China. However, the application of high strength structural steel is limited because of lacking sufficient experimental and theoretical study. To this end, this project will conduct a series of experiments on the material properties and the member behaviors of Q690 steel , including tensile coupon test, cyclic loading coupon test, measurement of residual stresses in welded wide flange Q690 steel H-section members, concentric and eccentric loading test of welded wide flange Q690 steel H-section columns, and cyclic loading test of welded wide flange Q690 steel H-section columns. According to these tests, material constitutive model, stress-strain hysteretic model and cumulative damage model of Q690 steel, residual stress distribution pattern and moment-curvature hysteretic model of welded wide flange Q690 steel H-section member will be developed. Moreover, numerical simulation models of the welded wide flange Q690 steel H-section columns under axial loading and under transversely quasi-static loading will be established and verified by comparing with the test result. With the verified numerical model, an extensive parametric analysis will be conducted, and the effect of the parameters on the ultimate bearing capacity and the ductility of Q690 steel columns under monotonic and cyclic loading will be discussed. Finally, the calculation and design methods of the ultimate bearing capacity of axially loaded Q690 steel column and the earthquake resistance of Q690 steel columns will be proposed based on the comparison of the ductility, expected reliability index and required earthquake action between Q690 high strength steel columns and those of conventional mild carbon steel (Q236, Q345) columns.

高强度结构钢的应用可有效节约用钢，为复杂结构提供合理解决方案。近年来，我国钢铁企业已研发生产了Q460~Q960高强度结构钢，但其设计和应用尚缺少理论依据和研究成果支持。本项目拟进行Q690钢单调和反复加载材性试验、Q690钢焊接宽翼缘H形截面构件的残余应力测试试验、Q690钢焊接宽翼缘H形截面柱受压极限承载力试验和水平反复加载试验；以得到Q690钢的基本力学参数及其统计参数、材料本构模型、滞回模型、累积损伤模型、残余应力分布模型、Q690钢柱的滞回模型；将各试验结果与残余应力数值模拟模型、钢柱受压极限承载力和水平反复加载数值模拟模型进行对比验证，采用验证后的数值模型进行系统的参数分析，总结归纳各参数对钢柱极限承载力、单调和反复加载下钢柱延性能力的影响规律；对照常规Q235、Q345钢柱的延性能力与目标可靠指标和地震作用要求的对应关系，最终提出Q690钢柱静力承载与抗震的计算和设计方法。

高强度结构钢在建筑工程中的应用不仅能有效节约用钢，还能为大型复杂结构提供更为合理的解决方案。近年来，我国钢铁企业已研发生产了Q460~Q960高强度结构钢，但其设计和应用尚缺少相应的理论依据和研究成果支持。本项目进行了Q690钢单调和反复加载材性试验、Q690钢焊接宽翼缘H形截面构件的残余应力测试试验、Q690钢焊接宽翼缘H形截面柱受压极限承载力试验和水平反复加载试验；基于试验结果提出了材料本构模型、滞回模型、累积损伤模型、残余应力分布模型、Q690钢柱的滞回模型；通过将验结果与残余应力数值模拟模型、钢柱受压极限承载力和水平反复加载数值模拟结果对比验证了数值模型，采用验证后的数值模型进行了系统的参数分析，总结归纳了各参数对钢柱极限承载力、单调和反复加载下钢柱延性能力的影响规律，最终提出了Q690钢柱静力承载与抗震的计算和设计方法。