Analytical Study on Cyclic Behavior of Steel Bridge Pier with Two-Surface Model

本研究包含以下两个主题：第一个主题是研究局部鸭化作用下钢桥墩的循环变形行为。首先，利用局部屈曲短柱的弯矩-推力-曲率曲线（M-P-phi曲线）编制了一个有限元程序，用于预测钢压弯构件的循环性能。利用编制的程序对钢桥墩的单调变形和循环变形进行了分析。计算结果与有限元程序ABAQUS和本文方法的计算结果比较表明，两者具有较好的一致性。因此，第二个研究主题的目的是发展塑性模型，可以考虑在合力空间的局部屈曲行为。利用所建立的塑性模型对钢桥墩进行梁单元分析，并与ABAQUS中的其他壳单元分析结果进行比较。

The present research consists of following two topics.The first research topic deals with cyclic deformation behavior of steel bridge piers due to the local duckling. Firstly, a finite element program has been developed to predict the cyclic behavior of steel beam-columns, using the moment-thrust-curvature curves (the M-P-phi curves) of locally buckled short-columns. Further, the monotonic and cyclic deformation of steel bridge piers has been analyzed with the developed program. Comparisons of the numerical results with the present approach and the finite element program ABAQUS have shown a relatively good agreement to each other.In general, it takes much time to analyze the local buckling behavior of steel tube bridge piers using the finite element method with the shell element. Therefore, the second research topic aims at the development of the plasticity model which can take into account the local buckling behavior in resultant force space. The beam element analysis is performed for the steel bridge pier with the developed plasticity model and the numerical results are compared with those of the other shell element analysis by ABAQUS.