严寒地区矩形钢管混凝土截面温度分布试验

Experiment on Temperature Distribution of Rectangular CFST Cross Section in Severe Cold Areas

为研究严寒地区钢-混凝土组合结构的温度荷载,以西宁市作为严寒地区的代表,在现场进行了水平放置带加劲肋的矩形钢管混凝土构件截面温度场测试试验,对日照作用下钢管混凝土构件截面温度分布进行了研究。同时还将矩形钢管混凝土构件的三维温度场简化为二维温度场,建立了ABAQUS有限元热力学分析模型,在考虑太阳辐射、风速以及环境温度等参数的作用下提出了构件截面温度场有限元计算方法。结果表明:钢管混凝土构件钢管测点及管内混凝土测点温度的实测值均与有限元计算值吻合良好;考虑日照作用的矩形钢管混凝土截面温度场为非均匀温度场,构件截面存在着明显的温度梯度;钢管温度受到环境温度的直接影响,其温度变化略微滞后于环境温度变化,温度极值明显大于环境温度极值;管内混凝土的温度则受到环境温度的间接影响,其温度变化明显滞后于环境温度变化,温度极值则小于钢管温度极值;矩形钢管混凝土截面温度分布还会受到管内纵向加劲肋的影响,该加劲肋增大了其与混凝土的接触面积,减少了管内混凝土温度变化的滞后程度,降低了构件截面的梯度温差。

In order to research the thermal load of steel concrete composite structures in severe cold areas,Xining was taken as a representative city in severe areas and the field test of temperature distribution of horizontal arranged rectangular concrete filled steel tube（CFST）member with longitudinal stiffeners was performed,the temperature field of CFST under solar radiation was researched.The three dimensional temperature filed of CFST member was simplified to two dimensional temperature filed,subsequently the thermal analysis model was built based on ABAQUS software,the finite element simulating method for temperature filed of CFST member was presented considering the parameters of solar radiation,wind speed and atmosphere temperature and etc.The results show that the calculating results of steel tube and in-filled concrete coincide well with the test data.The temperature field of rectangular CFST member under solar radiation is unsymmetrical,and there exists obvious thermal gradient.The temperature of steel tube is affected by the atmosphere temperature directly,thus causing thetemperature variation of steel tube lag behind the atmosphere temperature,and the temperature extreme value is much higher than atmosphere temperature.The temperature of in-filled concrete is affected by atmosphere temperature indirectly,which has a higher level of variation lag and the temperature extreme value is lower than that of the steel tube.The temperature of rectangular CFST member can also be affected by the longitudinal stiffeners in the steel tube,the stiffeners increase the contact area between steel tube and in-filled concrete,relieve the temperature variation lag of in-filled concrete and decrease the gradient temperature difference on the cross section of CFST members.