钢桁拱桥极值点失稳问题有限元分析  

Finite Element Analysis of Extreme Point Instability of Steel Trussed Arch Bridge

作　　者：刘洋 王楠 LIU Yang;WANG Nan(Wuhan Harbor Enginccring Quality Test Co,Ltd,Wuhan 430040,China;Hubei Key Laboratory of Advanced Materials ＆ Reinforcement Technology Research for Marine Environment Structures,Wuhan 430040,China;CCCC Wuhan Harbor Enginccring Dcsign ＆ Rcscarch Institutc Co,I.td,Wuhan 430040,China)

机构地区：[1]武汉港湾工程质量检测有限公司,武汉430040 [2]海工结构新材料及维护加固技术湖北省重点实验室,武汉430040 [3]中交武汉港湾工程设计研究院有限公司,武汉430040

出　　处：《建材世界》2018年第3期62-66,共5页The World of Building Materials

摘　　要：随着钢桁架拱桥的跨径不断加大,矢高增加,其施工中的稳定性问题表现得越来越突出,成为桥梁工程师关注的焦点之一。该文根据二阶静风稳定分析的基本理论,阐述了基于通用有限软件ANSYS的二阶静风稳定性的分析方法,并以一座跨径(70+240+70)m的下承式钢桁架拱桥为例,研究了该桥在施工过程中的一阶静风稳定性问题。结果表明:不考虑静风荷载时,施工前期结构整体刚度较大,屈曲模态表现为局部杆件面外屈曲,随着节段不断拼装,悬臂增大,结构整体刚度降低,整体失稳先于局部杆件屈曲;考虑静风荷载的一阶稳定性,结构的屈曲形式均表现为风撑斜杆的面外失稳破坏。As the span of the steel trussed arch bridge continues to increase and the vector height increases,the stability in its construction have become more and more prominent,becoming one of the focuses of the bridge engineers.Based on the basic theory of second-order static wind stability analysis,this paper describes the second-order static wind stability analysis method based on general-purpose finite software ANSYS,with a span-type（70＋240＋70）m of the steel trussed arch bridge as an example,the bridge is studied in the first-order calm wind stability problem in the process of construction.The results indicate that when static wind loads are not taken into consideration,the overall stiffness of the structure is large in the early stage of construction,and the buckling modes are manifested as the out-ofplane buckling of the local bar members,as the segments are continuously assembled,the cantilever is increased,the overall stiffness of the structure is reduced,the overall buckling instability before the local bar.Considering the first-order stability of the static wind load,the buckling form of the structure is manifested as the failure of the surface of the wind support diagonal.

关 键 词：钢桁架 失稳 有限元 

分 类 号：U448.22[建筑科学—桥梁与隧道工程]