Evaluation of maximum likelihood fitting for fragility analysis of code-designed steel plate shear walls

The steel plate shear wall (SPSW) presents a viable structural system to resist lateral forces during earthquakes. Although often designed based on the assumption that only steel plates attract seismic loading, the surrounding boundary moment resisting frame (MRF) from capacity-based design provides considerable capacity reserve. Fragility analysis studies the probability of collapse of a structure as a function of a certain ground motion (GM) intensity measure (IM). Collapse fragility analyses obtained through non-linear incremental dynamic analyses (IDA) under a set of specified earthquake ground motions provide a rational basis for determining building system performance and response parameters. This study evaluates the maximum likelihood method (MLE) for fragility analysis of SPSWs when they are close to collapse.