The Numerical Simulation On Mechanical Properties Of Steel Tube Reinforced Concrete Column Structure Under Sustained Loading And Impact After Fire

Composite component has many advantages such as high bearing capacity,good plasticity and fire resistance,simple production and so on.It is widely used in buildings.Due to frequent accidents,fire and explosion fragments produced by explosion has high impact energy,when debris role in supporting components,component under the impact of debris could reach its ultimate bearing capacity and damage,leading to building damage,destroy,or even collapse,the consequences to be reckoned with.In order to ensure the safety of the structure,the component has a certain high temperature impact resistance in the design,so as to reduce the chance of building collapse.Therefore,it is of great significance to further study the impact resistance of fire components.Using ABAQUS for the finite element simulation analysis,the research contents are as follows:Firstly,the paper summarizes the research status of the fire resistance performance and impact performance of the components at home and abroad,and selects the material parameters and constitutive relation of the model.On the basis of determining the selected parameters,the validity verification of the comparison test model is established,which indicates the rationality of the selected parameters.Secondly,the temperature field distribution of the fire is analyzed by selecting the proper heating curve,heat transfer equation and boundary conditions.The results show that the temperature field of the steel tube-reinforced concrete column is evenly distributed,and the temperature field shows a low trend.Then,research the load composite column under impact load by fire of the mechanical properties and working mechanism,from the impact,the deflection,stress state,energy conversion and residual bearing capacity analysis of the impact process.The results show that the composite column has good impact resistance.Finally,the affected by the impact properties of composite column of fire parameters,such as by fire time,slenderness ratio,impact velocity,section size,reinforcement ratio,steel ratio,steel parameters such as yield strength and concrete strength are analyzed.The main impact parameters have impact velocity,fire temperature,section size and steel ratio.The main influence parameters of span are impact velocity,length ratio,section size and reinforcement ratio.