寒潮所致混凝土箱梁桥温度应力分析

以降温幅度和降温持续时间为特征值构造了寒潮强度函数,引入箱梁截面基于传热学意义上的特征长度概念,采用ANSYS有限元软件按热传导第三类边界条件分析了某3跨等截面连续梁桥在各种强度的寒潮温度荷载作用下的瞬态温度分布和时程温度应力。考察了该桥的寒潮效应随寒潮强度、箱梁表面的对流换热系数和箱梁截面特征长度的变化而变化的规律,对混凝土箱梁桥寒潮温度效应的敏感影响因素进行了识别。

Thermal-mechanical Analysis of a Box-girder Bridge Under the Effect of Cold Wave

Taking cool down extent and length of time of this process as the characteristic values,the function that describes the magnitude of cold wave is established. The definition of section characteristic length is introduced. According to the heat conduction equation with the third boundary condition,the transient temperature and thermal stress distribution in a 3-span continuous box girder bridge with constant section under the attack of cold wave with many representative magnitudes is calculated by using the finite element software of ANSYS. The sensitivity of the thermal-mechanical behavior of the bridge towards cold wave magnitude,surface convection coefficient and section characteristic length is carried out.