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为了研究高层钢结构风致疲劳性能,提出了一种由整体尺度到局部节点尺度再到局部焊缝尺度的结构多尺度疲劳分析方法.选取某高层钢框架支撑结构为实际工程,模拟了相应的风荷载,通过建立结构的多尺度有限元模型,对模型进行时程分析,确定了结构应力较为集中的梁柱节点,并得到其应力集中的区域.然后,采用热点应力法对裂纹萌生寿命进行评估,并研究了单元类型及网格划分尺寸对结果的影响.结果表明:该结构底层边跨梁柱节点内侧梁上翼缘板的侧下部易产生较大的应力集中而萌生疲劳裂纹;对于焊缝附近的网格划分类型来说,线性单元及网格尺寸4 mm已基本满足精度需要;该工程的疲劳裂纹萌生寿命为335 a.
In order to study the wind-induced fatigue behavior of high-rise steel structures, a multi-scale fatigue analysis method of the structure from the global scale to the local node scale to the local weld seam scale is proposed. Taking a high-rise steel frame support structure as a practical project, Load, through the establishment of multi-scale finite element model of the structure, time-course analysis of the model to determine the structural stress is more concentrated beam and column nodes, and get the stress concentration area.Then, using hot spot stress method to crack initiation life assessment , And the effects of unit type and mesh size on the results are also studied.The results show that the stress concentration and fatigue cracks are easy to occur on the side lower part of the flange plate on the inner side beam of the girder at the bottom of the structure, For the mesh type, the linear unit and mesh size of 4 mm have basically met the need of precision. The fatigue crack initiation life of the project is 335 a.