Optimization Research Of Steel-concrete Composite Floor System Based On Ability Of Fire Resistence

Steel-concrete composite floor system has many advantages such as the light weight,the strong stiffness,the great assemblability,the convenience of construction and maintenance.Because of these advantages,the floor system can be used in the super high-rise building and the construction of industrialization.However,the fire resistance research of the steel-concrete composite floor system is still not deep enough due to the high cost in the fire test.So it is important to analyze the mechanical behavior of structure under fire by using finite element simulation.Simulating the testing slab and making a contrast between the testing result and the simulation result,which can verify the validity and feasibility.Based on this,it is feasible to make the varying parameter analysis and the fire-resistance optimization,which can not only reduce the cost,but also make the improvement and optimization of structural fire-resistance according to the optimization goals.In this paper,the main achievement can be summarized as follows:1?The reasonable thermal parameters are chosen.According to the structure and size of testing slab,the finite element model of composite floor system is built by the software of ABAQUS for the aim of analyzing the temperature field.Due to verify the accuracy of the results from the simulation,the temperature data of key points is obtained and compared with the testing results.Under this circumstance,the analysis of temperature development and distribution is done during the process of temperature rising.2? Under different temperature,the constitutive models of different materials are chosen.According to the structure and size of testing slab,the finite element model of steel-concrete composite floor system is built through the right definition of mesh generation?boundary condition and load.At the same time,the results obtained from the temperature are applied to the mechanical behaviour analysis of composite floor system under fire.Due to verify the accuracy of the results from the simulation,the data of mid-span deflection is extracted and verified with the testing results.The stress nephograms of concrete?profiled steel sheet and steel truss are exported to make a contrast between the stress distribution of normal temperature and high temperature,and the deflection and mechanic property of structure under fire can be analyzed.3?Based on the method of finite element simulation,the model of composite floorsystem is built according to the practical project.From the aspect of material grade ?component parts size and the form of truss,the most influenced facts on the mid-span deflection are found through the single varying parameter analysis.Based on the results,double varying parameters analysis is done to compare the results with the ones obtained from the single varying parameter analysis.The influence degree among different parameters can be observed.These analyses can provide some advices to the optimization design of composite floor system,which can help to achieve the goal of using the least material and making the lowest cost in the condition of making sure the mid-span deflection can not beyond the permissible deflection.