严寒地区高铁站台钢结构雨棚温度效应损伤分析

Analysis of Temperature Effect Damage of Steel Structure Canopy on High-Speed Railway Platforms in Severe Cold Regions

严寒地区高铁站台钢结构雨棚对温度效应异常敏感,季节性温差会引起结构产生较大的应力和变形,并导致结构损伤,影响铁路运营使用安全。为探究高铁站台钢结构雨棚损伤原因以及钢结构在温度效应下的力学性能,以严寒地区某高铁站台钢结构雨棚损伤为背景,采用Midas/Gen有限元分析软件建立雨棚模型,通过设置不同工况下的温度荷载变量,研究温度变化对钢结构的影响,探究其损伤机理。结果表明,温度变化会引起雨棚螺栓处的受剪及受拉状态变化,剪力增大较多,低温下容易发生脆性破坏;升、降温时雨棚桁架杆件应力均变化明显,会引起桁架杆件应力比超限,可导致该区域部分杆件出现开裂现象。采取释放檩托与檩条节点处螺栓约束措施,可大幅降低檩托所受应力及剪力,升降温工况下,檩托均不会发生破坏,能够满足站台雨棚使用要求。

The steel structure canopy of high-speed railway platforms in severe cold areas is extremely sensitive to temperature effects.Seasonal temperature differences can cause significant stress and deformation in the structure,leading to structural damage and affecting the safety of railway operation.To investigate the causes of damage to the steel structure canopy of high-speed railway platforms and the mechanical properties of steel structures under temperature effects,a canopy model was established using Midas/Gen finite element analysis software against the background of a certain high-speed railway platform steel structure canopy damage.By setting temperature load variables under different working conditions,the impact of temperature changes on the steel structure was studied and its damage mechanism was explored.The results indicate that temperature changes can cause changes in the shear and tensile states of the canopy bolts,with a significant increase in shear force and susceptibility to brittle failure at low temperatures;when the temperature is raised or lowered,the stress of the canopy truss members changes significantly,which can cause the stress ratio of the truss members to exceed the limit and lead to cracking of the members in this area.By taking measures to release the bolt constraints at the purlin bracket and purlin nodes,the stress and shear force on the purlin trailer can be significantly reduced.Under temperature rise and fall conditions,the purlin trailer will not be damaged and can meet the requirements for platform canopy use.