摘要
斜拉桥是由索、塔、梁形成的一种组合结构,主梁以压弯受力为主,主塔以心受压为主,因此结构的稳定性问题是斜拉桥设计中必须考虑的关键问题之一。在同时考虑几何非线性和材料破坏准确情况下的弹塑性稳定分析,实际上就是反映结构极限承载能力破坏的过程。为了分析组合梁斜拉桥的极限承载能力特性,文章利用ANSYS空间有限元模型研究了某大跨径组合梁斜拉桥的极限承载能力特性。分析了依托工程斜拉桥的极限破坏过程及其极限承载能力特性,得到了这种结构体系丧失承载能力的过程及破坏形态。研究表明这种结构首先在桥塔应力最大断面纤维进入塑性,主塔变形增大,然后轴力较大位置钢梁应力进入屈服阶段,形成结构体系的塑性铰,体系达到承载能力极限状态。文章的极限承载能力分析方法能够更加真实的反映斜拉桥结构的真实承载能力情况,可为类似结构研究提供借鉴。
The cable-stayed bridge is a kind of composite bridge combined by cables,towers and beams.The beam is mainly subject to compression and bending,and the tower is mainly subject to eccentric compression.Therefore,the stability of the structure is one of the key issues that must be considered in the design of the cable-stayed bridge.The elastoplastic stability analysis under the consideration of both geometric nonlinearity and accurate material failure is actually a process that reflects the ultimate load bearing capacity failure of the structure.In order to analyze the ultimate bearing capacity characteristics of the composite beam cable-stayed bridge,this paper uses ANSYS space finite element model to study the ultimate bearing capacity characteristics of a long-span composite cable-stayed bridge.The ultimate failure process of the cable-stayed bridge relying on the project and its characteristics of ultimate bearing capacity are analyzed,and the process of losing the bearing capacity and the failure form of this structural system are obtained.The research shows that this structure first enters the plasticity at the maximum stress section of the bridge tower and the deformation of the main tower increases,then the stress of the steel beam at the position where the axial force is large enters the yield stage,forming a plastic hinge of the structural system,and the system reaches the limit state of bearing capacity.The ultimate bearing capacity analysis method in this paper can more truly reflect the true bearing capacity of cable-stayed bridge structures,and can provide a reference for similar structure research.
作者
蒋皓
JIANG Hao(Jiangsu Zhongshe Group Co.,Ltd,Wuxi Jiangsu 214072 China)
出处
《江苏建筑》
2020年第2期51-54,共4页
Jiangsu Construction
关键词
斜拉桥
组合梁
极限承载能力
稳定分析
数值分析
cable-stayed bridge
composite beam
ultimate bearing capacity
stability analysis
numerical analysis