Numerical Simulation And Stability Research Of Reinforced Concrete Shear Wall Under Fire

In recent years,with the acceleration of urbanization,urban land resources have become lack,high-rise buildings and super high-rise buildings have become the mainstream development direction,which has put forward stricter requirements on the fire protection and fire resistance of structures.As one of the main structures of high-rise buildings and super high-rise buildings,concrete shear wall is urgently needed to be studied about its fire resistance.In this thesis COMSOL Multiphysics simulation software has been used to simulate and analyze reinforced concrete shear walls,especially the temperature field and stability under high temperature,to provide references for the fire protection design,evaluation and repair of high-rise buildings.The main research is as follows:(1)The COMSOL Multiphysics simulation software was utilized to simulate a three-dimensional numerical model of the shear wall temperature field.Compared and verified with the experimental findings,the fire and heat insulation suggestions of shear walls with different wall thicknesses were given.(2)On the basis of the verified temperature field model,the parameter research on the temperature field of reinforced concrete wall was carried out,and thereby the influences of some potential factors,including the heating curve,number of fire surfaces,thickness of concrete cover,heat transfer boundary conditions,and reinforcement ratio were analyzed.Subsequently,the variation trends for the wall temperature field affected by the above parameters were obtained.(3)The COMSOL Multiphysics simulation software was utilized to develop 3D thermal-mechanical coupled numerical simulation of the reinforced concrete shear wall.The simulation results were compared with the previous experimental results,and then to verify the rationality of the numerical simulation results.(4)The internal force and deformation of the shear wall under high temperature and vertical load were calculated using the established shear wall thermal-mechanical coupling numerical model,and the influences of height-to-thickness ratio,reinforcement amount,end restraint,fire duration,different surfaces exposed fire on the overall stability of shear wall under fire environment were analyzed.The changing rules of displacement curves and stress nephogram were obtained.According to the simulation results obtained,a formula for calculating the critical bearding capacity for the shear wall was revised for its overall stability affected by the vertical load under fire conditions.