Study On Seismic Damage Model Of Multi-aged Steel Frame Members&Seismic Fragility Analysis Of Multi-aged Steel Frame

Seismic damage model of multi-aged steel frame members&seismic fragilityanalysis of multi-aged steel frame has been studied in this paper through thecombination of experiment and numerical simulation.Degradation law of mechanical properties of steel and seismic damage evolutionprocess of steel frame columns in acidic atmosphere which is simulated by aerosolcorrosion box has been studied in this paper. The degeneration law of strength,stiffnessand the energy dissipation capacity of steel frame columns was investigated through lowcycle reversed loading tests of12frame column specimens with various loading, axialcompression ratio and the degree of corrosion. And the seismic damage evolutionprocess of steel frame columns could be concluded through the analysis of testing datewhich could be divided into three stages: producing, developing stably and developingrapidly. And the influence of the degree of corrosion, axial compression ratio, loadingcycle number and other design parameters, on the damage of specimens has also beenanalyzed, which would be a support for a new damage model which would be putforward in this paper. In view of the deficiencies of the existing damage model, a newdamage model would be put forward in this paper which is consider of loading mode,loading path, cycle times and the change of yield displacement. And the relatedparameters has been studied. The new damage model could describe the development ofdamage in the loading process well through the calculated value contrasts with testingdata, and a new index about seismic fortification would be put forward. According to the combination of material test and steel corrosion in real acidicatmospheric environment, degradation rules of mechanical properties with the ages hasbeen obtained. Four kinds of steel frames(0year,15years,30years,45years) has beenselected to suffer15seismic waves whose amplitude would be regulated12times byABAQUS. And intercalation displacement angle is used as a performance criteria onsteel frame to do analysis of the seismic vulnerability. The results show that with theincreasing of age, the probability of steel frame structure beyond a limit state would beincrease in the same seismic intensity.