Non-uniform steel strip dampers subjected to cyclic loadings

• Based on flexural behavior, simplified design methods for strip dampers are provided.
• Non-uniform strip shapes were well designed to improve structural performance.
• Damage and fatigue cracks are widely distributed over the entire height of the strips.
• The proposed dampers showed significantly improved ductility and energy dissipation.
• The suggested design equations can accurately predict the structural characteristics.

This paper describes the cyclic performance of non-uniform steel strip dampers. The shapes proposed are (a) a dumbbell-shaped strip, (b) a tapered strip, and (c) an hourglass-shaped strip. Each of these strip shapes was designed to reduce stress concentration when subjected to cyclic loadings. In order to evaluate the performance of the dampers, six specimens were tested cyclically. Cumulative damage caused by hysteretic motion was effectively distributed throughout the entire height of the strips, and SEM microstructures of the fracture surfaces represented a typical ductile failure mode. The experimental results showed that the proposed strip dampers indicate excellent seismic performance compared to conventional prismatic slit dampers. Furthermore, it was verified that structural performance can be accurately estimated using the design equations presented in the paper.