Numerical Simulation On The Failure Mechanism Of FRP Reinforced Concrete Beams Under High Temperature

With the development of social economy,the frame,shear wall and reinforced concrete structures are more and more,and the fire protection of concrete members is becoming more and more serious,which has attracted wide attention of researchers.Fiber reinforced plastic(FRP)as a substitute for steel,with corrosion resistance,light weight,high strength,anti fatigue,penetrating electromagnetic wave and other excellent properties,and has wide application prospect.FRP tendons are made of carbon fiber,glass fiber,aramid fiber and other high performance fibers through the pulling extrusion process,the mechanical properties,durability,fire resistance and reinforcement have a greater difference.Currently researches at home and abroad about FRP tendons concrete components,mechanical properties and durability,fire resistance research is less,it is necessary to a thorough study on FRP fire resistance of concrete structures and failure mechanism.This paper mainly through of fire(high temperature)of FRP reinforced concrete beams flexural bearing capacity and shear strength are studied,the object of study for FRP reinforced concrete beams.Through the comparison of ABAQUS software analysis of FRP reinforced concrete beam under the action of high temperature temperature changes,resulting in FRP reinforced concrete beam changes in capacity,by drawing force calculation formula of bearing capacity of reinforced concrete beams under the normal temperature,thus initially get a FRP reinforced concrete beam under high temperature flexural and shear force calculation method.The main research contents of this paper include the following aspects:(1)Analysis of the comparison of the domestic and foreign scholars about FRP tendons concrete component and high temperature fire-resistant performance of FRP reinforced concrete beams research results,select appropriate FRP and concrete under the room temperature and high temperature of thermal and mechanical properties,the establishment of FRP reinforced concrete beam temperature field analysis of the model.(2)The mature international organization for standardization the ISO834 standard heating curve and of FRP reinforced concrete beam section temperature field in three sides under fire conditions was simulated by using finite element analysis software ABAQUS,in order to get the temperature change of the section beam isotherm distribution and FRP tendons and compared under the condition of high temperature at different times of beam section temperature field distribution.(3)Using the calculation principle of the equivalent section method,through the reference temperature of the reinforced concrete beam bearing capacity calculation,FRP reinforced concrete beam under the action of high temperature bearing force calculation method was presented,and the calculation of beam under the action of fire at different times of the bearing force changes,compared to the ABAQUS simulation results verify failure mechanism is in accordance with the specification in the strong shear weak flexure design requirements.