Research On The Seismic Damage And Collapse Of Steel Frame Structure

Compared with reinforced concrete structure, steel structures are widely used inlarge shopping malls, office buildings, schools, residences, factories and other buildings,because of theirs excellent seismic performance and good economic benefits. Steelframe structure will continue to play an important role in the civil engineeringconstruction for a long time in the future. The earthquake will cause the buildingstructure damage, and the damage will be gradually accumulated with the increase inthe number of loading cycles. Damage accumulation will cause mechanicalperformance degradation of materials, components and even the structure, resulting ingradual reducing of the carrying capacity and the stiffness. In this paper, themulti-storey steel frame structure is the research object. Numerical method whichstudies the damage evolution law of frame structures under seismic excitation, thenstorey damage model and structural damage model are founded, the seismicperformances of the frame structure with different section corrosion rates are studied bytaking fragility analyses with the finite element analysis software, OpenSEES, based onthe incremental dynamics analysis. The study contents are given as follows:1. The bending stiffness is treated as damage characterization of the frame beamand the ultimate energy dissipation capacity is counted as the frame columns’ in thispaper. The damage sensitivity analysis is carried out for design parameters, such as webheight, web thickness, flange width, flange thickness, is conducted by calculating, andthe damage law that the main design parameters of the steel cross-section steel framebeam and column is revealed.2. The displacement is treated as damage characterization of storey. Based on ABAQUS, numerical simulation theory and numerical simulation analysis of thestorey damage evolution of steel frame structure under cyclic loading are established,then component damage and storey damage evolution are revealed and the function thatreflects the influence of the ratio of column to beam, height to width,axial-compression ratio of frame columns and steel corrosion rate on storey damage isachieved, and storey damage model which applies to steel frame structure is finalized.3. The5-storey steel frame structure is taken as the research object andinterlaminar participation coefficient of storey hysteretic property. Characterizationfunction of the structural damage is constructed by taking the weighted partialcoefficient method. The damaged model of the entire structure is achieved, withstuding the impact of the number, location and extent of damage storey.4. Selection criteria of ground motion records and seismic strength index is given.Seismic response analyses of steel frame structure are conducted and the key questionsrelated to analyses. The finite element model is established with the finite elementanalysis software, OpenSEES. Based on the incremental dynamics analysis, the fragilityanalyses of the frame structure with different section corrosion rates are conducted.Finally, the fragility curves are depicted...