Finite Element Analysis Of Shear Behavior Of Double Tees Tongue And Groove Under Fire

Fire is a major hidden danger affecting the safety of buildings.With the development of the times,there are more and more buildings.Prefabricated building has become the core industry of construction industrialization at home and abroad.Because of the progress of equipment and materials,as well as the detailed specifications and standards issued by foreign countries,the prefabricated components develop rapidly,and the Double-Tees emerges as the times require.Because the research on Double-Tees started late in China,the research results are relatively less.The United States invented a kind of tongue-and-groove type Double-Tees,and published the relevant specifications.Although there are some research and application in China,it is not comprehensive and has certain limitations.How to improve the fire resistance and shear performance of Double-Tees tongue-and-groove end is a very important topic,so this paper will mainly study the fire resistance and shear performance of Double-Tees tongue-and-groove end.(1)Firstly,the research object is determined as the tongue-and-groove end of Double-Tees,and the main factors affecting the shear performance of tongue-and-groove end of Double-Tees at room temperature are studied.By changing the length of tongue-and-groove,vertical hanging reinforcement,concrete strength,thickness of concrete cover and reinforcement ratio of stirrup at the protruding end,the influence on shear performance of tongue-and-groove end of Double-Tees at room temperature is analyzed.(2)The temperature field model of Double-Tees under fire is established to analyze the cross-section temperature distribution of Double-Tees under different fire time.Under the same fire time,the temperature changes of special points and reinforcement at different distances from the cross section of Double-Tees to the fire surface are analyzed.(3)The finite element analysis model of shear performance of Double-Tees tongue-and-groove end under fire is established.Under the condition of constant load and temperature rise,the effects of different tongue-and-groove length,vertical hanging reinforcement,concrete strength,concrete cover thickness and stirrup reinforcement ratio on the fire resistance of Double-Tees tongue-and-groove end under fire are analyzed.Under different fire time,the tongue-and-groove length,vertical hanging reinforcement and concrete reinforcement ratio are analyzed The influence of concrete strength,concrete cover thickness and stirrup reinforcement ratio on the ultimate load of tongue-and-groove end of Double-Tees is analyzed,and the ultimate load at room temperature is compared.On the basis of the research results,the rules are summarized to provide a theoretical basis for the design of Double-Tees fire resistance,so as to be applied in engineering.