The Study On Reference Air Temperature And The Temperature Effect Of The Large Span Steel Structure

Large span steel structure has been developed,and the temperature is more sensitive to the steel structure.The basic temperature is the reference value for determining the function of temperature,and it is necessary to determine the meteorological parameters of the structural loads."Load coad for the design of building structures" GB50009 on the basic temperature has a clear definition,as the average maximum and minimum temperature monthly.However,for the steel structure whose heat transfer rate is fast,they are sensitive to the change of temperature.The structure temperature is closer to the highest temperature and the lowest temperature yearly.So it is necessary to revise the basic temperature in the design of steel structure.For large span structure,not only by the effect of temperature,wind loads are more pronounced than earthquake sometimes.Therefore,the combination of temperature effect of the wind is a essential design.The load combination factor plays an important role in load combinations.However,load combination factor of the temperature and wind load is the result of long experience accumulated as amended,and is not considered due to the impact load correlated with a randomly generated source.Combination factor based more on experience,we need to determine more scientific rationalization on combination factor.Load coad for the design of building structures" GB50009 at the specified load combinations,when taking into account two or more loads on the structure,the load is unlikely to occur simultaneously with its maximum load representative value and we use the combination value of loads.However,when snowstorms occur,not only accompanied by huge snow loads,extremely low temperatures,but also often accompanied by greater wind.Therefore,we should analyze the respond to the structure under extreme weather.In the process of the building structure,we often do not consider the impact of the process on the structure.But large span steel structure is statically indeterminate structure,for statically indeterminate structure,temperature changes can not only cause deformation of the structure,but also temperature stress structures.The residual stress of temperature in the structure can not be ignored as the initial stress state,and should be considered in the structural design.In this paper,as 631 stations nationwide annual highest temperature and lowest temperature since 1951 the sample,basic temperature in various regions of the 50-year return period is obtained,and is compared with the current load specification.Taking into account the correlation between wind and temperature effects,load combination factor will be adusted to ensure the safety design of steel structures based on historical data of wind speed and temperature in the major regions of the country by comparing the actual weather response with load code combination.Static analysis will be done on the constructed project on blizzard weather conditions indicating that the adverse effects of blizzard weather conditions and make relevant recommendations of the load combination factor.This article will simulate the construction process of different span reticulated shell and obtain the structure residual stress of the temperature when completed to offer the reference to the future structure design.