Study On Fire Resistance Of Composite Columns With Corrugated Steel Webs

Corrugated steel web composite column is a new type of composite structure,which benefits from the excellent buckling resistance of corrugated steel webs.The corrugated steel web composite column has the remarkable advantages of high bearing capacity,convenient construction and good economy,it has been applied well in large span and heavy load structure.Because corrugated steel webs and four-corner steel tubes are located at the outermost side of the columns,they are easily influenced by the heat flow under high temperature of fire,which leads to the damage of the columns bearing capacity and stiffness,even the destruction of the columns.However,at present,the fire resistance of corrugated steel webs is lack of necessary knowledge,which limits the engineering application of this kind of structure to some extent.Therefore,it is necessary to study the fire-resistant performance and fire-resistant protection methods in order to provide a basis for fire-resistant design of corrugated steel webs composite columns.In this paper,a finite element model of corrugated steel web composite column is designed and its fire resistance is analyzed.The main research work is as follows:(1)The finite element analysis model of corrugated steel web composite columns at normal temperature is established by Abaqus,and the ultimate bearing capacity of composite columns at normal temperature is obtained.(2)The finite element model of corrugated steel web composite columns is established.The model is applied to analyze the mechanical properties and failure mechanism of composite columns.(3)The influence of fire load ratio,load eccentricity ratio,section size and steel tube thickness on the fire resistance of composite columns is analyzed.The influence of each parameter on the axial deformation and fire resistance of composite columns is studied,a simplified formula for calculating the fire resistance of composite columns with corrugated steel webs under different parameters is given.(4)The fire resistance of composite columns with corrugated steel webs subjected to fire on three sides is analyzed,including the distribution of temperature field and the failure mechanism of the columns.(5)The fire resistance of composite columns with corrugated steel webs coated with cement mortar and fire retardant coatings is analyzed,and the Change Law of fire resistance limit under different thickness of protective coatings is studied,the suggested values of the thickness of the protective layer of the composite columns with different parameters are given.