摘要
研究目的:针对全焊接钢桁架桥中次应力对桥梁结构设计的影响,以某公路钢桁架桥为例,运用有限元软件ANSYS对结构进行计算,建立该桥理想铰接模型和节点刚性模型,计算由节点刚性所引起的结构次应力。研究结论:通过对两种模型应力的计算分析,得出了桁架次应力的大小及分布特征,结果表明:次应力对下弦杆、上弦杆、斜腹杆影响力依次增大;支座所在节间,下弦杆产生较大次应力,需加强支座处各杆设计。由于节点的近乎刚性,在实际桁架的杆件中不可避免的存在次应力,因此在实际的结构设计中,应该通过有限元的计算来确定次应力对结构的不利影响,不宜轻易改变上下弦杆截面。
Research purposes： Taking a Highway Steel Truss Bridge as an example, this paper studies the impact of secondary stress on structure design of the fully welded steel truss bridges. This bridge was simulated by using ANSYS finite element software. The ideal hinges model and the rigid truss nodes model were built in order to calculate the secondary stress caused by rigid truss nodes. Research conclusions： By analyzing the stresses of two models, the value and distribution characteristics of the secondary stress were obtained. The results showed that the influences of secondary stress on the lower boom, top boom and diagonal web members increased successively. In the node with supporting seal, the booms on the supporting seal would be strengthened because of the bigger secondary stress of lower boom. The secondary stress existed inevitably in the actual truss rod because of rigid truss nodes. So, in the actual structure design, the calculation with finite element would be made to define the adverse effects of secondary stress on the structure and the cross - section of booms would not be changed generally.
出处
《铁道工程学报》
EI
北大核心
2012年第12期72-77,共6页
Journal of Railway Engineering Society
关键词
钢桁架桥
ANSYS
有限元
节点刚性
次应力
steel truss bridges
ANSYS
finite element
rigid truss node
secondary stress
