既有铆接钢桁梁桥热铆加固工艺数值模拟分析

Numerical Analysis of Hot Riveting Reinforcement Technology for Existing Riveted Steel Truss Girder Bridge

为了解既有铆接钢桁梁桥加固过程中热铆残余应力对结构受力性能的影响,以重庆牛角沱嘉陵江大桥为背景,采用Abaqus软件建立铆接接头数值模型,基于温度-位移耦合分析,研究热铆工艺全过程热铆残余应力的分布特征和影响效应。结果表明:基于温度-位移耦合分析方法的热铆过程数值模型计算结果与试验结果吻合良好,能够大幅提高求解效率和收敛性;铆接过程中,铆钉和铆孔局部范围发生屈服并产生热铆残余应力,铆孔沿板厚方向的残余压应力大于轴向;拼接板与铆钉接触范围大,其热铆残余应力大于铆接板;热铆残余应力在一定程度上提高了结构的受力性能,不考虑热铆残余应力将大大降低评估结果的准确性。

During the strengthening of the existing riveted steel truss girder bridge,the hot riveting process can induce residual stresses in the truss members which are possible to exert effects on the structural performance of the bridge.Based on the Niujiaotuo Jialingjiang River Bridge in Chongqing,the riveted joints were numerically simulated by Abaqus.The distribution characteristics and influential effect of the residual stresses induced in the whole hot riveting process using the coupled temperature-displacement analysis method.The numerical simulation and test results agree well,indicating that the coupled temperature-displacement analysis can remarkably improve the computational efficiency and convergence.During the hot riveting process,the rivets and the local parts of the rivet holes yielded,where residual stresses were observed,with the residual stresses along the plate thickness of the rivet hole bigger than the residual stresses along the axial direction.As the contact area between the splicing plates and the rivets is large,the residual stresses in the splicing plates are bigger than those in the riveting plates.The hot riveting induced residual stress,to a certain extent,improves the structural performance of the bridge,if omitted,the evaluation accuracy would be discounted.