基于Ottosen准则的PC多梁式梁桥全过程分析  

Whole-Process Analysis of PC Multi-Girder Bridge Based on Ottosen's Criterion

作　　者：张剑[1] 叶见曙[2] 余波[3] 

机构地区：[1]南京航空航天大学结构工程与力学系,江苏南京210016 [2]东南大学桥梁工程研究所,江苏南京210096 [3]江苏省交通科学研究院股份有限公司,江苏南京210017

出　　处：《华南理工大学学报（自然科学版）》2009年第9期24-29,共6页Journal of South China University of Technology(Natural Science Edition)

基　　金：国家"863"高技术计划项目(2007-AA11Z106);西部交通建设科技项目(200331822315);南京航空航天大学引进人才基金资助项目(S0851-013)

摘　　要：为了对预应力混凝土(PC)多梁式梁桥进行非线性全过程分析,采用弥散裂缝模式、Ottosen屈服准则和Hinton压碎准则描述混凝土的开裂、屈服和压碎等非线性变化,引入实体退化壳单元理论,对混凝土和普通钢筋采用分层壳单元模拟,预应力钢筋采用组合壳单元模拟,并根据位移协调性推导了预应力钢筋对组合壳单元刚度矩阵的贡献,提出了一种非线性组合?分层壳单元计算模型,并编制了相应的三维非线性壳单元计算程序.结合破坏性试验资料可知,非线性计算结果与试验数据吻合良好,极限荷载的相对误差约为0.13%;同时,普通钢筋和预应力钢筋应力发展规律的研究表明,对于PC多梁式梁桥这类薄壁结构,采用文中提出的非线性壳单元计算模型来研究其破坏全过程是有效的,此单元具有良好的数值稳定性和收敛性.This paper aims at the nonlinear whole-process analysis of prestressed concrete（PC） multi-girder bridges.In the investigation,first,nonlinear variations of the concrete including cracking,yielding and crushing are described respectively based on the smearing crack model,Ottosen s yielding criterion and the Hinton crushing theory.Next,with the help of degraded shell element,the concrete and the common steel are simulated using the layered shell element and the prestressed steel is simulated using the combined shell element. Then, the contribution of the prestressed steel to the stiffness matrix of the combined shell element is investigated according to the displacement coordination. Moreover, a nonlinear combined-layered shell element model is established and the corresponding analytical procedure is programmed, by which a 3D nonlinear calculation is performed, finding that the calculated results accord well with the results of failure experiment of a PC multi-girder bridge, with a relative error of the ultimate bearing capacity of about 0. 13%. Finally, the regularities of stress redistribution of the prestressed steel and the common steel are analyzed, showing that the proposed nonlinear shell element with excellent numerical stability and convergence is suitable for the whole-process analysis of thin-wall structures such as PC multi-girder bridges.

关 键 词：预应力混凝土 多梁式梁桥 全过程分析 Ottosen准则 非线性 组合壳单元 数值稳定性 

分 类 号：U441.2[建筑科学—桥梁与隧道工程]