Reliability-based evaluation of design and performance of steel self-centering moment frames

Recently developed steel self-centering moment-resisting frames (SC-MRFs) have been analytically and experimentally validated as having the potential to eliminate structural damage under a design basis earthquake and restore their original vertical position following a major earthquake. Using Monte Carlo simulation, we subjected three nonlinear models of prototype SC-MRFs to thousands of synthetic ground motions, and recorded peak demand responses such as story drift and beam-column relative rotation. We used this data to examine the sensitivity of SC-MRF behavior to structural properties and geometry, seeking to generate recommendations to improve the existing design procedure. A reliability-based methodology was used to assess the likelihood of reaching the limit state of post-tensioned strand yielding. This study proposes modifications to the existing design procedure and illustrates a reliability-based methodology for developing improved seismic design recommendations.

Research highlights
► Seismic performance of steel post-tensionedmoment-resisting frames is assessed.
► These frames self-center after an earthquake and sustain nostructural damage.
► Nonlinear models of frames are subject to a large suite of synthetic ground motions.
► The likelihood of reaching a key limit state of PT strand yielding is determined.
► A reliability-based method for developing improved design recommendations is outlined.