钢管混凝土拱桥的动力稳定极限承载力研究

从结构极限承载力的角度研究钢管混凝土拱桥在地震作用下的动力稳定性能。基于大型通用有限元程序ANSYS的应用平台,使用其APDL语言,采用B-R运动准则结合动态增量法(IDA)提出用特征响应寻求钢管混凝土拱桥动力稳定极限承载力的研究方法,分析地震动输入方向、结构几何非线性、材料非线性及其结构初始缺陷模式和大小对动力稳定极限承载力的影响,结果表明横向输入对拱桥稳定最为不利,材料非线性的影响比几何非线性影响大,几何初始缺陷会降低拱桥的动力稳定极限承载力,其中以反对称最为不利。最后,通过对一钢管混凝土模型拱桥的振动台试验的分析比较,表明该方法的正确性和工程适用性,可为系统研究钢管混凝土拱桥的动力稳定性能提供理论分析基础。

A study on the dynamic ultimate capacity of CFST arch bridges

The dynamic stability of concrete filled steel tubular(CFST)arch bridges under earthquakes is studied with respect to the structural ultimate bearing capacity.Based on the finite element software package(ANSYS),a method for using representative responses to study the dynamic ultimate capacity of CFST arch bridges is proposed by application of Incremental Dynamic Analysis in combination with the B-R dynamic criteria.The influence factors,such as earthquake input directions,geometric and material non-linearities,and the initial imperfection modes and magnitudes,are investigated.The results indicate that the bridge is affected the most by lateral earthquake input,that material non-linearity has a more serious effect than geometric non-linearity,and that the initial imperfection reduces the ultimate capacity,and the anti-symmetrical mode might be the worst case.The method is compared with a CFST model arch shaking table test,the result of which indicates that the method proposed is correct and applicable in engineering practice.