Research On Mechanical Behavior Of Single-storey Steel Frame Structure Workshop Under Corrosive Environment

With the vigorous development of China’s steel industry,steel structure building with the increase of steel output and gradually rise.The steel structure has the advantages of light weight,high strength,good toughness and easy installation in the construction site,which improves the safety of the building and saves time in the process of site installation.Therefore,steel structure form has been widely used in building structure.The safety problem of steel structure building has been paid more and more attention in engineering field.Many steel structure buildings in Marine atmosphere,industrial atmosphere and other corrosive environment for a long time will appear corrosion problems.The corrosion of steel structure will reduce the effective section size of structural members and the strength,elastic modulus and other mechanical properties of steel structure materials.The corrosion of steel structure can be divided into uniform corrosion and local corrosion.Among them,the biggest harm to steel structure is local corrosion,local corrosion of steel structure will cause steel members in the local effective section area is reduced,stress concentration phenomenon,while the physical and chemical properties of steel will change.The overall bearing capacity and seismic performance of steel members under local corrosion will decrease,which will affect the safety of the structure and increase the probability of safety accidents.Therefore,it is necessary to study the mechanical properties of steel structures under local corrosion.The bearing capacity and stress state of steel columns in a single layer steel frame structure under different local corrosion degree were studied by taking a single layer steel frame workshop in coastal area as an example.Mechanical behavior of monolithic monolayer steel frame structure under different local corrosion.(1)SAP2000 finite element software is used to establish a single-layer steel frame workshop model,analyze its stress state under static force,find a transverse frame with the largest internal force from the overall steel frame structure,and analyze the internal force of each frame column.(2)ABAQUS finite element software is used to simulate and analyze the ultimate bearing capacity of each frame column without corrosion.In case of local corrosion of steel column,three conditions are considered: In this paper,the bearing capacity and stress state of steel column are studied under different conditions,such as local corrosion at different positions of steel column flange,local corrosion at different areas of steel column flange and local corrosion at column bottom web.It is found that the local corrosion of steel column occurs at the flange of steel column and has a greater influence on the bending capacity of H-shaped steel column than the local corrosion of steel column web.Local corrosion occurs in steel columns,and when the central section of local corrosion is 1/3 away from the bottom of the column,the bearing capacity of steel columns decreases most obviously,which makes steel columns prone to damage.When the local corrosion degree of steel column increases,the stress concentration phenomenon is most obvious at the local corrosion of the column,while when the local corrosion degree is small,the stress concentration phenomenon is most obvious at the beam-column junction of the inner flange of the column.(3)In the case of local corrosion of single-storey steel frame workshop structure,the stress state of the overall structure of steel frame was analyzed under static and dynamic conditions,and compared with the overall structure without corrosion.The mechanical behavior of single-storey steel frame workshop structure under multiple local corrosion conditions was studied.It can be concluded that,under the vertical load,the maximum stress and maximum displacement of all frame columns in the periphery of the overall structure increased by 19.6% and 9.1% when local corrosion occurred compared with those of non-corroded structures.Under the action of horizontal earthquake,the lateral stiffness of the whole structure with locally corroded steel columns in the periphery of the structure decreases obviously,the horizontal seismic force decreases slightly,and the horizontal displacement increases slightly compared with that of the uncorroded structure.The frequency of the whole steel frame structure under local corrosion decreases by 8.55% compared with that of the uncorroded structure,and the vibration modes of the whole structure and the uncorroded structure under local corrosion are basically the same.