Temperature Effects And Welding Effects On Long-span Steel Arch Structure

With advantages of unique appearance and better space utilization, the steel arch is being adopted in more and more construction as the long-span structure develops in China. However, this trend also brings some new problems, during which the temperature effect and welding effect are the prominent ones. Under the complex temperature field, the temperature stress and strain are produced in the members and structures when the thermal expansions are not flexible. In addition, the non-uniform temperature field during the welding process results in complex residual stress, which also presents unfavorable effect on the structure. Under the engineering background of Hohhot Baita Airport Terminal, the temperature effect and welding effect of the long-span steel arch were studied.Firstly, the species of temperature effects and the reasons of the temperature stress and strain were introduced, followed by the analysis of the temperature gradient, the temperature self-restrained stress and thermperature inferior stress induced by sunshine temperature difference. The results refer to the influence of the solar radiation on the steel arch.The model of the whole structure was built, and the accurate temperature differences and the most disadvantageous combination of internal force were imposed to analyze the influence of the gravity and temperature on the arches and the influence of the temperature on the arches when they were put in the whole structure under the work loading.What's more, in order to stimulate the welding effects, the models of welding plate and the cross-section of weld seem were bulit. The weld process was simulated with the birth-death element and transient analysis function of ANSYS. The discussion of the result refers to the value and distribution of the residual stress.Finally, the development trend of the stress on the arch was put forwards based on the previous results. The feature of structural failure resulted from the temperature and welding effects was summarized. It is considered that the temperature effects and welding effects are significant in the crack of the structure. Some improvement measures were also put forwards.