Parametric Study of an Angled U‑Shaped Damper Arrangement for Strengthening Structures

In this study, an angled U-shaped damper was proposed in an innovative arrangement. Nonlinear static analyses considered damper dimensions and installation angle as the main variables. The evaluated responses included energy dissipation, equivalent damping coefficient, effective and elastic stiffness, and maximum strength, and approximate predictive equations were developed. Increasing the damper angle generated additional bending and torsional moments, causing earlier yielding and reducing seismic performance. Additional analyses showed that inclined configurations improve out-of-plane resistance, while installation angle also governs variable-amplitude cyclic behavior and the strength, stiffness, and cumulative energy dissipation of AUD-equipped steel frames.