基于多尺度有限元的钢桁架整体节点疲劳性能分析和试验研究

Analysis of Fatigue Performance of Steel Truss Girder Integral Panel Points Based on Multi-Scale Finite Element and Experimental Study

为了简化结构疲劳分析,提高计算效率,以大连星海湾大桥(主跨460m的3跨双层地锚式悬索桥)为背景,采用多尺度有限元方法对该桥钢桁加劲梁进行疲劳性能分析,整体节点板部分采用三维实体单元,传力构件采用普通梁单元,用Arlequin方法模拟耦合区域。进行了1∶2缩尺模型整体节点疲劳试验,将测点应力值与多尺度有限元分析值进行对比。研究结果表明,多尺度有限元分析值与试验值吻合良好,应用多尺度有限元分析结构疲劳性能是可靠的。多尺度有限元方法对结构主要研究部位进行准确模拟,减少了模型中的节点数和单元数,提高了计算效率,可以作为疲劳分析的一种新方法。

To sim plify the analytical process of the fatigue perform ance and im prove the efficiencyof calculation,the three-span earth-anchored suspension bridge of the Xinghai Bay Bridge inD alian,having a m ain span of460m,w as taken as the study background.T he m ulti-scale finiteelem ent m ethod w as used to analyze the fatigue perform ance of the stiffening girder of the bridge.T he part of the integral gusset plates w ere m odeled by three-dim ensional solid elem ents,the loadtransferring com ponents w ere m odeled by com m on beam elem ents,and the coupling regions w erem odeled by A rlequin m ethod,to conduct m ulti-scale finite elem ent analysis.A1:2scale modelw as prepared for the fatigue te stin g,and the m easured stress values at the testing points w erecom pared w ith the calculated values by the finite elem ent calculation.T he results of the study indicatethat the fatigue safety coefficients of the integral panel points of the steel tru ss of the XinghaiBay Bridge in Dalian is greater than5and the fatigue perform ance m eets the service requirem ents.T he values gained from m ulti-scale finite elem ent analysis are close to those from the experim entalstudy,and it is reliable to analyze the fatigue perform ance of the structure by using m ulti-scale finiteelem ent m ethod.U sing the m ulti-scale finite elem ent m ethod can accurately sim ulate the mainstructural parts for the study,reduce the num ber of panel points and elem ents and im prove the efficiencyof the calculation.