钢桁架-混凝土组合结构温度作用下剪力滞效应  

Shear lag effect of steel truss-concrete composite structure under temperature action

作　　者：任文辉 赵晓翠 马彦阳 朱良 REN Wenhui;ZHAO Xiaocui;MA Yanyang;ZHU Liang(China Railway Construction Shaanxi Expressway Co.,Ltd.,Xi’an 710064,China;School of Highway,Chang’an University,Xi’an 710064,China)

机构地区：[1]中铁建陕西高速公路有限公司,陕西西安710064 [2]长安大学公路学院,陕西西安710064

出　　处：《西安科技大学学报》2022年第5期985-993,共9页Journal of Xi’an University of Science and Technology

基　　金：陕西省交通运输科研项目(20-45K)。

摘　　要：为研究钢桁架-混凝土组合结构在温度作用下的剪力滞效应并计算有效分布宽度。以某钢桁架-混凝土组合结构为研究案例,采用ANSYS建立空间有限元模型,选取6个截面作为研究对象,分析整体升温20℃,整体降温20℃以及温度梯度升、降温作用下的桥面板上缘正应力分布情况,对比常温下的正应力分布情况,研究剪力滞效应随温度作用的变化规律,采用应力合力与有效分布宽度内实际最大正应力合力相等的原则计算有效分布宽度。研究结果表明:钢桁架-混凝土组合结构在常温下,距支点四分之一跨径的桥面板正应力值由边支点向跨中方向逐渐减小,中跨跨中正应力值大于边跨跨中。整体升温和降温对组合结构剪力滞效应影响程度相近,方向相反。温度梯度变化对组合结构剪力滞效应影响较大,最大应力变化幅度超过200%,需在组合结构设计时予以考虑。在温度作用下,升温和降温分别使有效分布宽度变大和变小的趋势。In order to study shear lag effect of steel truss-concrete composite structure under temperature action and calculate the effective distribution width, a steel truss-concrete composite structure is taken as a case study to establish spatial finite element model by ANSYS.Six sections are selected as the research objects to analyze the normal stress distribution on the upper edge of the bridge deck under the effects of overall temperature rise of 20 ℃,overall temperature drop of 20 ℃,temperature gradient rise and temperature drop.The distribution of normal stress at room temperature is compared to study the change law of shear lag effect with temperature.The effective distribution width is calculated based on the principle that the stress resultant force is equal to the actual maximum normal stress resultant force within the effective distribution width.The results show that, at room temperature, the normal stress value of the bridge deck of the steel truss concrete composite structure with a quarter span from the fulcrum gradually decreases from the side fulcrum to the middle of the span, and the normal stress value in the middle of the middle span is greater than that in the middle of the side span.The effects of overall heating and cooling on shear lag effect of composite structures are similar in opposite directions.The change of temperature gradient has great influence on the shear lag effect of the composite structure, and the maximum stress variation is more than 200%,which should be considered in the design of the composite structure.Under the action of temperature, heating and cooling make the effective distribution width larger and smaller, respectively.

关 键 词：钢桁架-混凝土组合结构 温度作用 剪力滞效应 有效分布宽度 

分 类 号：U448.216[建筑科学—桥梁与隧道工程]