Impact of Horizontal Boundary Elements Design on Seismic Behavior of Steel Plate Shear Walls

Keywords: Steel plate shear walls (SPSW).  Seismic performance.  Horizontal boundary elements (HBE). Plastic hinge formation.  Pushover analyses.  Nonlinear time-history analyses.  Deformations.  Ground motion.  Strength.  Cyclic loading tests.

Abstract: A case study was conducted to investigate the seismic behavior of steel plate shear walls (SPSW) having boundary elements designed by two different philosophies.  The first design approach does not guarantee that formation of in-span plastic hinges on horizontal boundary elements (HBE) will be prevented; while the second approach guarantees that plastic hinges can only occur at the ends of HBEs.  Pushover and nonlinear time-history analyses were conducted to investigate behavior.  Results show that the development of in-span plastic hinges has significant consequences on the behavior of the structure.  Nonlinear time-history analyses also demonstrated that increasing the severity of the ground excitations acting on the structure with in-span plastic hinge accentuated the accumulation of plastic incremental deformations on the HBEs.  In addition, this study investigates plastic strength of SPSW having in-span plastic hinges and develops an alternative plastic mechanism needed to match results from pushover analysis.  A cycle by cycle investigation on HBE deformation history under cyclic loading was presented and several key behaviors observed during the cyclic loading history were identified.