Numerical Simulation Research On Fire Behavior Of Composite Deck Slabs

Steel deck-concrete composite slab (hereinafter for short: composite slab), as a very reasonable structure where steel and concrete material strength are completely utilized, has quick construction, good ductility and higher anti-earthquake capacity. At the present time, specific method is still ambiguous in criterion, and it also can't meet the needs of engineering development. Therefore, a thorough study of fire resistance and fire resistance design method of profiled steel-composite deck slabs has great theoretical value and practical significance.As finite element software, ANSYS is used to analyze performance of profiled steel deck-concrete composite slab under fire in this paper, and testifies that the theory is right and the result is accurate and reliable, the main research work includes as follows:Firstly, FEM analysis of temperature distribution of composite deck slabs under firea) Appropriate FEM models and material models are selected to make the simulation result and the experiment result coincident, the accuracy of this simulation method is verified;b) Thermal contact resistance on the interface of steel and concrete is considered and implemented;c) The parameters of composite deck slabs are changed, and the influence on the temperature distribution caused by them is analyzed.Secondly, fire resistance performance research of composite deck slabs under thermal-mechanical couplinga) The structural model and element type are selected and the results of simulation are compared;b) The geometry non-linearity properties and the material non-linearity properties are considered to make the simulation result and experiment result inosculated;c) The impact caused by parameters of the structure is analyzed and the rules of fire resistance are summarized.At last, the fire-resistance performance of simple-support slabs and continuous slabs is studied, and the influence of several parameters on performance of composite slab is analyzed, such as steel thickness, slab thickness, slab span, and the distribution of reinforcing steel bars. So the research conclusions provide theoretical basis for rational choosing parameters of profiled deck in practice.The following contents are innovative in the research field:a) In this paper, 2D and 3D FEM models of the composite deck slabs are built. The impact caused by profiled-sheet and reinforcing steel bar on the temperature distribution of the whole slab is studied in different models. The thermal contact resistance effect between the steel and concrete is discussed and the numerical simulation research is implemented according to the correlative experimental data;b) The processing technology about the mesh is developed when the element types of profiled-steel sheeting, reinforcing steel bar and concrete are used in the different FEM models.