Study On Temperature Distribution Of Concrete-filled Steel Tubular Sections Under Solar Radiation

Concrete-filled steel tube is widely used in civil engineering structure, which is especially used in the bridge engineering. While the more domestic research is focused on the temperature resistance performance of concrete-filled steel tubular structure, and the less research is focused on the structural performance under solar radiation. The temperature effect of concrete filled steel tubular arch rib is produced by solar radiation, which has significant impact on the entire bridge, therefore it is necessary to research the characteristics of temperature distribution and its effect of the concrete-filled steel tubular section.First of all the basic characteristics of solar radiation are outlined, then the basic calculation methods of solar radiation and heat transfer theories are summed up. Complex heated environment of different sectional forms of concrete filled steel tubular element under solar radiation are simulated through the large scale finite element analysis software ANSYS, and the temperature distribution of section is obtained. At last, temperature field analysis of section under different environment are carried out through the parameters sensitivity analysis.The main conclusion are as follows:(1) The thermal parameters and environmental parameters of concrete-filled steel tubular materials are determined through the methods of field test, then the method of temperature field analysis is adopted and the APDL parametric language is drew up, which can analyse the temperature field of component section accurately under solar radiation in any location, any climatic conditions and any seasonal time.(2) The process of daily temperature variation is shown up as the characteristics of sine function distribution, the solar radiation absorption rate of steel tube outside surface is the largest factor on influencing the temperature distribution of section in many meteorological parameters and concrete thermal parameters.(3) In the temperature distribution of the circular cross section of arch rib component, the more concrete measure point near the centre, the smaller the temperature range is and the later the maximum value appear. The temperature distribution of section is appeared in highly nonlinear characteristic under solar radiation The significance are as follows:(1) The temperature distribution and effects of concrete-filled steel tubular section are researched, which can help engineers to calculate temperature load correctly when analysing the concrete-filled steel tubular structure, and provide effective theoretical guidance for the temperature stress analysis in the operational stage.(2) The input of heat flux density is achieved through the parametric design language in ANSYS, which is efficient and accurate in calculation results, and can auxiliary calculate the temperature stress of element under solar radiation during the structural design in the future.