Nonlinear Research With Thermal-Structure Analyses Of Low Layer And Unprotected Frame Steel Under Fire

Steel has many excellences, but its Fire resistance. At elevatedtemperatures, Steel shows the different Structural characteristics anddeformation processes from normal state. Therefore when Steelconstruction did not take fire prevention measures or fire protection isnot sufficient for, once a fire calamity happening, structure willbe vulnerable to destruction and even collapse, making a serious threatto human life and property safety. The cost of fire resistant facilities andfire test are very expensive, and the fire resistant of structural membersbetween test conditions and real fire conditions is different, so it is veryimportant and necessary to analyze steel members and structures responseat elevated temperature with computer numerical simulation. Steel frame,The overall structure is more than one order of statically indeterminatestructure, the failure of individual rods is not equivalent to the entirestructure fail. Some part of the components become invalid, redistributionof internal forces between whole components will make the expiring member forces pass to the connected components which has not beendamaged by interactions. Thus causing the entire structure keeps onaccepting loads.After consulting other research results and reading lots of papers, thisthesis composes of these parts. Firstly, material properties of the differentcountry and the organization at elevated temperature are sorted out,through an example of analyzing the temperature of a light beam.Comparing the results from ANSYS and literature[37], explains therationality and reliability of the numerical simulation analysis. Firesimulation of frame models are set up by ANSYS software. Obtained thebeam and column’s process of heat transferring and warming law, thenwhich compare with the result of the formula in literature [37], they have agood correlation. Makes a pilot study on the effect from section’s shape totemperature; Secondly, analyze the entire structure’s process of forcingand deformation by thermal-structure analysis, determines the weak linkof the structure in the fire; Thirdly, study on steel frame shows thedifferent Structural characteristics and deformation processes under thedifferent scenes, analyzing with or without stiffener, changing differentlocations of fire occurres, changing different curves of fire,changingcomponent’s different states in fire,discuss their influences to the structure.The last advances some reference value suggestions and conclusions tothe actual engineering design.