双柱墩地震反应分析中非线性单元的选用

摘要

以常用的三种非线性梁柱单元为例,研究了双柱桥墩抗震分析的单元选取问题,结果表明,不同单元的选取对双柱墩的位移反应影响不大;采用集中塑性M铰单元时计算最简便,地震内力响应误差也最大;采用集中塑性PM铰单元时弹性内力响应会被较大地低估,但不改变结构的极限承载力;分布塑性纤维单元可以考虑轴力—强度及轴力—刚度耦合作用,但计算最为复杂。%Taking three kinds of common non-linear beam-column units as an example,this paper studies the selection of double-column pier seismic analysis.Results show that： different unit selection doesn＇t have great impact on the displacement of double-column pier,while using central plastic M unit,the calculation is rather simple and the internal seismic stress error is the greatest,while using central plastic PM unit,the internal elastic stress will be lower without changing the ultimate loading,while distributing plastic fiber unit,the coupled function of axis force-strength and axis force-rigid,but the calculation will be most complicated.