Study On The Temperature Field And Thermal Stress Numerical Analysis Of Concrete-Filled Steel Tube

For the concrete filled steel tube (CFST), the confinement effect of steel tube to the core concrete makes the core concrete in the state of being compressed from three dimensions, at the same time, due to the supporting effect to the steel tube from the core concrete, the occurrence of local buckling of the steel tube is avoid or delayed. The CFST makes the advantages of both materials brought into full play. Therefore, the CFST material is a superior performance of construction materials.Steel tube and core concrete interface to maintain close contact is the premise to play the superior performance of CFST materials. Since the thermal performances of steel tube and the core concrete are very different, If the radial temperature tensile stress generated by the service environment temperature changes is greater than the bond strength between steel tube and concrete, This will result in the steel tube and core concrete interface separation, which is not conducive to play the material prosperities of the CFST.This paper, based on the National Natural Science Foundation of the Interface characteristics and performance optimization of CFST under the Service environment, consulting a large number of related literature references, adopts numerical analysis method to study on the Temperature field and thermal stress. The specific works as follows:1. By reading the relevant literature and research findings, Awareness to the dangers of environmental Temperature changes on the CFST structure, Master the latest research progress on the temperature problem of CFST. By analyzing and summarizing the impact factor of the temperature field of CFST structure on the basis of understanding the basic theory of Heat transfer, deduced the finite element basic equations of plane transient temperature field, detailed overview of the derivation of CFST cross-section finite-element method for transient temperature field.2. Based on mastering the basic theory of the thermo-elasticity, derived the analytical solution of temperature stress of CFST circular cross section which contains the Axis-symmetric distributions of temperature. Respectively, use the analytical formula and ANSYS finite element software to calculate the thermal stress, and the accuracy of the calculation results is verified to two methods through comparative analysis of calculation results.3. In order to study the adaptability of concrete filled steel tubular structural components to harsh environments and provide theoretical guidance for the following Thermal Shock Test, In this paper, giving full consideration to the conditions of the test specimen, test equipment and reasonably determining the specimen in the case of the shock chamber heat transfer assumptions, Numerical Simulation of Thermal Shock Test of CFST test specimen in the temperature from-20℃to60℃by large universal finite element software ANSYS, According to analyze the finite element simulation results and draw the useful suggestions for engineering practice.