Optimizing stiffener orientation in cold-formed shear panel dampers for enhanced ductility and energy dissipation

Abstract

Shear panel dampers (SPDs) are essential passive energy dissipation devices in earthquake-resistant structures, designed to yield in shear before other primary members, thereby mitigating seismic damage. The hysteretic response of SPDs is significantly affected by stiffener configurations on their webs, which prevent shear buckling. This study investigates SPDs with three distinct stiffener orientations (transverse, longitudinal, and diagonal) to identify the optimal configuration for enhanced ductility and energy dissipation. A 3D finite element model was developed in ANSYS Workbench to analyze SPDs under lateral cyclic loading, incorporating geometric imperfections and material nonlinearity. The model was validated against experimental data, confirming its accuracy. Subsequently, 18 SPDs, fabricated from cold-formed steel and cold-formed stainless steel, were numerically analyzed to evaluate their hysteretic performance. Results indicate that both transversely stiffened (TSPDs) and longitudinally stiffened (LSPDs) SPDs exhibited more stable hysteretic responses than diagonally stiffened (DSPDs). While DSPDs showed higher initial shear capacity, they demonstrated diminished ductility and energy dissipation due to rapid strength deterioration. LSPDs consistently outperformed TSPDs in buckling resistance, deformation capacity, ductility, and overall energy dissipation. Based on these findings, preliminary predictive design formulae for cold-formed stainless steel LSPDs were derived, offering valuable insights for optimized design.