钢-混凝土结合梁试件降温与升温过程的数值计算  

Numerical Calculation of Steel-Concrete Composite Beam Specimen in its Temperature Dropping and Rising Process

作　　者：陈焕新[1] 刘蔚巍[1] 刘凤珍[1] 

机构地区：[1]中南大学土木建筑学院,湖南长沙410075

出　　处：《中南大学学报（自然科学版）》2005年第2期335-339,共5页Journal of Central South University:Science and Technology

基　　金：铁道部计划项目(2002G025)

摘　　要：根据非稳态导热的控制微分方程,建立了钢混凝土结合梁试件降温与升温过程的数学模型。将恒热流的三维导热问题视为相应的3个一维导热问题的叠加,并采用有限差分法对控制微分方程进行离散,对钢混凝土结合梁试件在强迫对流环境下的降温(25^-45 ℃)和自然对流环境下的升温(-45~25 ℃)中的温度分布进行了数值计算。研究结果表明:在降温与升温过程中,钢混凝土结合梁试件内部各点温度变化速率不相同,导致试件内温度分布不均匀,形成了温度梯度;气温的较大变化会使钢混凝土结构内部温度分布不均匀,由此产生的温度应力可能会破坏桥梁结构。According to the differential control equations of three-dimensional unsteady thermal conduction, a numerical model was developed for calculating temperature distribution in temperature dropping and rising process of steel-concrete composite beam specimen. A three-dimensional unsteady thermal conduction was treated as three one-dimensional unsteady thermal conductions, and the process of temperature dropping in force convection and temperature rising in natural convection was calculated. The calculation results indicate that different temperature changing velocities of different points cause the temperature not to be distributed well in the specimen, which induce temperature gradients. Great variations of air temperature will make temperature not well distributed in steel-concrete constructions, and temperature stress caused by temperature gradients will make great crevices on bridges.

关 键 词：桥粱工程 温度分布 数值计算 钢-混凝土结合粱 

分 类 号：U448.216[建筑科学—桥梁与隧道工程] TB657.3[交通运输工程—道路与铁道工程]