Buckling-restrained brace frame structure with a rational damage order and failure mechanism under the action of earthquake,could be regarded as the ideal structural system with multichannel seismic line.To research the damage of buckling-restrained brace frame under earthquake,floor damage model based on damage models of frame column,frame beam and buckling-restrained brace members using the weighted partial coefficient method was used to build the global damage model and the damage states and corresponding damage index range of buckling-restrained brace frame were defined by combining the damage indexes.Buckling-restrained brace frame structure vulnerability curves considering the ground motion uncertainty and uncertainty of the structure were compared by IDA analysis.The results showed that,in the collapsed state,the difference is not obvious,and under the collapsed state,logarithmic standard deviation increased when considering structure uncertainty.The fragility curves were compared by using the maximum inter storey displacement angle and the damage index structure of the structure.
