Q460高强度钢材焊接T形截面压杆整体稳定性能研究

Application of the high strength steel in steel structures are taken as the research background of this project. Overall buckling behavior of high strength steel struts are studied through theoretical analysis and experimental study. That is one of the newest research topics in the world. The main content of this project is as following: 1) The specimens of Q460 high strength steel welded T-struts are tested to obtain the properties of steel, the initial geometric imperfection and sectional residunal stress for being used in the theoretical analysis. The specimens of Q460 high strength steel welded T-struts are tested to obtain the ultimate bearing capacity for verifying the FEA method. 2) Based on the FEA of T-struts with the initial bending, loading eccentricity and sectional residunal stress on the experimental results, the overall buckling mechanism of high strength steel welded T-struts is revealed. 3) By the numerical models with the simplification of initial geometric imperfections and residual stresses, the ultimate bearing capacity of high strength steel welded T-struts with different dimension are computed by the FEA method. Comparing the results of the Code with that of the FEA method, the design method and recommendations of the overall buckling of high strength steel welded T-struts will be proposed from the aforemention study. The research result of this project are expected to resolve the basic problems of the overall buckling design of high strength steel welded T-struts, and also expected to provide reference and theoretical basis for the popularization and application of high strength steel in building structures.

以高强度钢材在建筑钢结构中的应用为研究背景，采用理论分析与试验研究相结合的方法研究高强度钢压杆的整体稳定性能，属国际最新前沿课题之一。 主要研究内容包括：1）开展Q460高强度钢材焊接T形截面压杆极限承载力试验，获得钢材材性、构件几何初始缺陷及残余应力实测值，为理论分析提供依据；获得压杆极限承载力试验值，为验证有限元方法的正确性提供依据；2）通过考虑了实测初弯曲、初偏心以及残余应力等因素影响的压杆整体稳定性能数值分析，揭示高强度钢材焊接T形截面压杆整体失稳机理；3）利用基于简化初始几何缺陷及残余应力模型的有限元方法对不同尺寸的高强度钢材焊接T形截面压杆极限承载力进行计算，将其结果与现行规范的计算结果加以对比，提出高强度钢材焊接T形截面压杆整体稳定设计的合理化方法和建议。 研究成果可望解决高强度钢材焊接T形截面压杆整体稳定设计中的基本问题，为高强度钢材在建筑结构中的推广应用提供参考和依据。

以高强度钢材在建筑钢结构中的应用为研究背景，采用理论分析与试验研究相结合的方法研究高强度钢压杆的整体稳定性能，属国际最新前沿课题之一。项目以Q460高强度钢材焊接T形截面压杆为对象，开展构件整体稳定极限承载力理论及试验研究，主要内容及研究结论如下：1）完成Q460高强度钢材焊接T形截面压杆极限承载力试验，获得钢材材性、构件几何初始缺陷及残余应力实测值，为理论分析提供依据；获得压杆极限承载力试验值，为验证有限元方法的正确性提供依据；2）通过考虑了实测初弯曲、初偏心以及残余应力等因素影响的压杆整体稳定性能数值分析，揭示高强度钢材焊接T形截面压杆整体失稳机理；3）修正了T形截面钢压杆弯扭屈曲稳定系数简化计算公式；利用基于简化初始几何缺陷及残余应力模型的有限元方法对不同尺寸的高强度钢材焊接T形截面压杆极限承载力进行计算，将其结果与现行规范的计算结果加以对比，提出高强度钢材焊接T形截面压杆整体稳定设计的合理化方法和建议。上述研究成果初步解决了高强度钢材焊接T形截面压杆整体稳定设计中的基本问题，可为高强度钢材在建筑结构中的推广应用提供参考和依据。