Assessment of Floor Accelerations in Yielding Buildings

Keywords: OpenSees.  Finite element (FE) analyses.  Three-dimensional (3D) models.  Steel moment frame structures.  Incremental dynamic analyses (IDA).  Peak floor response.  Structural periods.  Ductility.  Horizontal floor acceleration.  Vertical floor acceleration.  Seismic building codes.  Ground motion.  Seismc performance.

Abstract: The present study uses the OpenSees finite element framework to develop full three-dimensional models of four steel moment frame buildings. The incremental dynamic analysis method is employed to evaluate the floor response of inelastic steel moment frame buildings subjected to all three components of a suite of 21 ground motions. To better understand the acceleration demands on nonstructural components, this study focuses on the influence of structural period, level of ductility, of the structure, and relative height in the building on the horizontal and vertical floor acceleration response. As a result of this study, a more realistic formulation of the peak floor acceleration response accounting for the effect of structural period and ductility is proposed and may be used to improve current code estimations is proposed. In addition, a direct method for developing an envelope horizontal floor response spectrum is developed.