Response Analysis Of Steel Frame During Overall Local Room Fire Process Of Heating And Cooling

This paper mainly presents systematic results on the response analysis ofsteel frame during overall local room fire process of heating and cooling by themethod of numerical simulation and puts toward the corresponding proposalabout fire resistance design and strengthening after fire.The main work done inthis paper is as follows:1. The study on internal temperature field distribution of component duringoverall fire process of heating and cooling. Transient thermal analysis programfor fire was composed for plane steel frame based on finite element method andtemperature field analysis during overall fire process of heating and cooling onthe components of fire room was carried out,involving the characteristics ofroom fire and change of structural steel material properties with temperature andISO834standard heating and cooling temperature curve generally used at homeand abroad was used to simulate the development process of environmentaltemperature during fire process. Sectional temperature distribution and change of the components of fire room during overall fire process of heating andcooling was obtained by studying.2.The study on response of steel frame during overall local fire process ofheating and cooling. Thermal-structural coupled analysis program for the overallfire process of heating and cooling was composed based on finite elementmethod and real-time simulation of three-layer three-span steel frame under firein the local room was analyzed, involving the geometricnonlinearity,non-uniform distribution of temperature field and the change ofstructural steel mechanical properties with temperature. The change rule ofdeformation and internal forces of steel frame during fire process of heating andcooling were obtained and some proposals about fire resistance design andstrengthening of steel frame after fire were put toward.3.The parametric analysis was carried out to mainly determine the effect ofthe position of fire room,the initial stress ratio,the heating rate and the coolingrate.The results indicate that the response of steel frame increases when theposition of fire room located on the underlay or mindspan.The more the initialstress ratio is,the more the deformation and internal forces during overall local fire process of heating and cooling are.The faster the heating rate is,the moreobvious the structure response at the same time is.The faster the cooling rate,thefaster the deformation and internal forces restores.