多肋式梁桥在全过程中应力重分布研究

张剑¹, 黄剑峰², 叶见曙³, 俞博³

1.南京航空航天大学结构工程与力学系;2.云南农业大学水利水电与建筑学院;3.东南大学桥梁工程研究所



摘要:

为了考察多肋式梁在全过程中受力性能,利用非线性实体退化壳单元理论研究了多肋式梁的应力重分布规律.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,推导了预应力钢筋对组合壳单元刚度矩阵的贡献和统一的非线性壳单元模式.利用Owen屈服准则、Hinton压碎准则和弹塑性强化模型考虑了混凝土和钢筋的非线性效应,有效模拟了预应力混凝土多肋式梁的开裂、屈服和失效全过程,并编制了相应的三维非线性全过程计算程序.结合破坏性试验资料可知,理论计算结果与试验数据吻合良好,并对预应力钢筋应力发展规律进行研究.结果表明,用实体退化壳单元模拟预应力混凝土多肋式梁是合适的,研制的非线性单元和非线性程序是正确的.

关键词:  多肋式梁  应力重分布  非线性  实体退化壳单元  组合单元

DOI：10.11918/j.issn.0367-6234.2010.10.029

分类号:U441.5

基金项目:交通部西部交通建设科技项目(200331822315);南京航空航天大学引进人才科研基金(S0851-013)



Stress redistribution analysis of multi-girder structure during the whole course

ZHANG Jian¹, HUANG Jian-feng², YE Jian-shu³, YU Bo³

1.Department of Mechanics and Structural Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China;2.Faculty of Water Resources,Hydraulic Power and Architecture,Yunnan Agricultural University,Kunming 650201,China;3.Bridge Engineering Institute,Southeast University,Nanjing 210096,China)

Abstract:

In order to grasp the mechanism of the multi-girder structure during the whole course,the stress redistribution regularity is studied with shell element degraded from solid element.Steel and concrete are depicted by layered shell element and the prestressed steel is modeled by combined shell element.Then the stiffness matrix of contribution of the prestressed steel to the combined shell element is deduced.Respectively based on Owen yielding theory and Hinton crushing theory and bilinear model,the material nonlinear properties of concrete and steel are considered.Then the procession of cracking,yielding and failure of prestressed concrete multi-T girders is imitated and the analytical procedure is compiled.Through compared with the failure experiment results of a prestressed concrete multi-T girder bridge,the calculations are in good agreements with them.The regularity of stress redistribution of prestressed steel is studied.It shows that it is feasible to apply shell element degraded from solid element to depict the prestressed concrete multi-T girder bridge and the corresponding computational method and procedure for nonlinear whole-course analysis are correct and reliable.

Key words:  multi girders  stress redistribution  nonlinearity  degraded shell element  combined element