Numerical Simulation Of Precast Concrete Double-tee Floor To Fire

After years of development,China's construction industry has made rapid progress.With the large-scale development of industrial buildings and the continuous reform of industrial styles,the applicable scope of dual-T prestressed concrete slab has also started to broaden and widen.Its clean appearance,simplicity of design,shorter construction period and more saving of construction resources are also an issue.However,the mechanical behavior of prestressed concrete structures under fire is very complicated.Precast prestressed concrete double T panels are generally used in large-span and large-space structures.The load of the prestressed concrete structures is very high.In the event of fire,the components are destroyed.The occurrence of collapse,the consequences unimaginable,and therefore to strengthen its research on the fire resistance performance is particularly important.In this paper,the idea of performance-based fire prevention is used to analyze and study the mechanical properties of pre-stressed double T-plate under high temperature.The fire curve simulated by pyrosim software can be more realistic to restore the actual fire situation on the one hand,As the span of the prestressed double T-plate is too large,the whole uniform heating will not occur.When the positions of the fire sources are different,the temperature away from the fire source will also have a certain gap from the fire source center.Generally speaking,the whole heat will be affected Therefore,this paper starts from the fire curve and simulates the advanced fire situation,and then selects the representative curve to simulate it by using the finite element software ABAQUS.This article mainly did the following work:(1)FDS software Pyrosim prestressed double T plate placed in a relatively real fire situation,to its possible fire situation simulation,by changing the location of the fire source,ventilation conditions to observe the different fire conditions The observed temperature difference between the double T plate and the relative real fire rise curve are compared with the ISO international temperature rise curve to provide the basis for the next step finite element analysis.(2)Under the condition of high temperature in fire,the mechanical and thermal properties of the reinforced concrete have some changes,all the parameters are summarized and analyzed in this paper;(3)The finite element analysis of prestressed double-T plate is carried out by using ABAQUS software.Firstly,the temperature field of double-T plate is explored and analyzed.According to the results of the second chapter,two kinds of fire heating methods are selected,Uniform heating and overall heating,the influence of different curves on the temperature field of the double T plate is discussed.The second part is the analysis of the relevant mechanical properties of the above conditions,and the deflection of the dual T plate under different fire curves is obtained Changes and fire resistance limits.