Research On Temperature Effect On Single-layer Latticed Dome With Glass Roof From Construction To Service Period

In order to narrow the gap between indoor and outdoor space,In recent years,daylighting roofs,such as membrane roof and glass roof,are more and more used in engineering.The result is the temperature effect of the structure under the roof.Steel structure is temperature sensitive structure.Temperature may be the main control load in structural design in some large span structures.There are many kinds of glass used in roof of building structure,in order to provide the basis for the temperature effect of large-span space structure under glass roof,Its solar radiation characteristics are to be studied.The structure is exposed to sunlight during the construction phase,periodic variation of temperature effect caused by solar radiation.At present,domestic and foreign scholars mainly study the influence of construction mechanics behavior during construction.Due to the time-varying temperature in the construction phase,The residual stress can not be ignored as the initial stress of the structure.The main research work includes:An experiment is carried out to explore the transmission coefficient of 16 different hollow glass such as clear glass,Futelanmo glass,Lanxinghumo glass,etc.The time-varying temperature under each kind of glass and the solar radiation transmittance of different glass were obtained.By simplifying the Fresnel formula,The transmission rate of each kinds of glass was obtained.It provides the basis for calculating the temperature effect of the space structure under the glass roof.Based on the transmittance of glass obtained from the solar radiation characteristic test of glass roof in space structure and ASHRAE model for thermal analysis finite element theory.Time dependent temperature field and structural thermal stress of single-layer reticulated shell under radiation in summer in Tianjin area are analyzed.The distribution law of temperature stress field and the variation law of structural stress with temperature and time are obtained.It provides the basis for the analysis and calculation of the temperature stress of the reticulated shell under the glass roof.Considering the effect of solar radiation temperature during the construction stage of single-layer reticulated shell,nine models were established according todifferent span and ratio of rise to span.The structure is divided into five construction sections,the construction process is modeled by a modeled batch activation.Due to the complex and changeable construction process environment,therefore,each construction section is set to 20℃,30℃,40℃,50℃,60℃,a total of five kinds of temperature changes,During the simulation,the temperature values of the construction sections are arranged and combined,the most unfavorable influence on the structure was analyzed and the distribution of temperature residual stress in construction process was obtained.The bearing capacity of single-layer reticulated shell structure is generally controlled by stability,the residual stress of the construction process as the initial stress of the structure will inevitably affect the stability and bearing capacity of the structure.Finite element analysis results of single-layer reticulated shell during construction,the whole process of load and displacement is analyzed considering the temperature variation during construction,the first order buckling eigenvalue and ultimate bearing capacity of the structure are analyzed with the variation of residual stress.The safety factor correction value considering the temperature residual stress in the construction process is proposed in the structural design stage.It provides the basis for single-layer reticulated shell structure design.