钢结构风致疲劳分析的多尺度有限元验证分析

为了研究钢结构风致疲劳分析中的多尺度有限元建模技术并验证其合理性，选择某二层框架结构，分别采用约束方程法和子模型法建立多尺度有限元模型，进行风荷载静力分析、动力时程分析及风致疲劳分析，并将计算结果与单一尺度模型进行比较，研究各多尺度有限元模型的特点，在此基础上研究局部细观尺度模型区域大小的选择.结果表明：在静力分析、动力时程分析及疲劳分析中，多尺度模型的计算结果与单一尺度模型吻合较好，精度可满足工程需要；子模型法相对约束方程法的精度更高，但更易受局部模型区域大小的影响.针对与本工程梁柱尺寸相似的钢框架结构，建议当采用约束方程法时，边界离研究部位横向轴线的距离选为0.05 m，而当采用子模型法时选为0.10 m.
Abstract: A two-layer frame structure was selected, and multi-scale finite element models were established by the constraint equation method and the sub-model method respectively, in order to study the multi-scale finite element modeling technology of steel structures under wind and to verify its rationality. Wind load static analysis, dynamic time history analysis and wind-induced fatigue analysis were performed; the obtained results were compared with those of single-scale models; the characteristics of those multi-scale finite element model were studied. Based on these, the selection of local micro scale model size was studied. Results show that in static analysis, dynamic time history analysis and fatigue analysis, the results of multi-scale models are in good agreement with those of single-scale models and the accuracy can meet the engineering demand. The sub-model method is more accurate than the constraint equation method, but is more sensitive to the local model size. For those steel frame structures with similar beam and column size to this structure, the distance between the boundary and the horizontal axis of the research location is recommended to be 0.05 m when the constraint equation method is used, while to be 0.1 m when the sub-model method is used.