基于多尺度模型的襄阳东津站铸钢节点动力弹塑性分析

ELASTIC-PLASTIC ANALYSIS OF THE CAST STEEL JOINTS OF DONGJIN RAILWAY STATION IN XIANGYANG BASED ON A MULTI-SCALE MODEL

针对关键节点的细部分析,采用从整体模型中隔离出节点,将整体模型与节点模型分别独立计算的方法,在节点域施加的边界条件往往与实际情况相差较大。应用多尺度建模技术对东津站屋盖铸钢节点进行动力弹塑性分析。屋盖杆件采用梁单元建模,关键节点采用实体单元进行精细化建模,并通过自由度约束方程对梁单元和实体单元进行多尺度连接,从而准确反映节点域的边界条件。分别采用多尺度建模和隔离体建模进行对比分析:在结构整体地震动响应方面,两者的计算结果基本一致,多尺度建模仅对节点域相邻区域的杆件有一定影响;在节点域的计算分析方面,采用隔离体的节点分析结果偏于保守。研究表明,多尺度建模技术精确描述节点边界条件,是分析复杂结构关键节点的一种有效手段。

Finite element analysis of critical joints based on nodal isolation will introduce false boundary conditions and lead to unreliable results.A multi-scale model was built to conduct the dynamic elastic-plastic analysis of the critical joints of the Dongjin Railway Station roof structure.The members of roof structure were dispersed with beam elements and the critical nodal domains were analyzed with a 3D refined model discreted by solid elements.In order to apply an exact boundary condition of the nodal domain,the multi-point constraint equation was adopted to connect beam elements and solid element.The comparative analysis of multi-scale modeling and isolation modeling was conducted,it could be concluded that the multi-scale modeling would change the seismic response of the bars of adjacent nodal domain but had little effect on the global seismic response.The resules showed that the multi-scale model could provide a detailed boundary condition of the key nodal domain,which was an effective method for analyzing the critical joints of the complex structures.