Experimental Response of Friction‐Based Dissipative Braces for Steel Seismic‐Resilient Concentrically Braced Frames

Abstract Concentrically Braced Frames (CBFs) represent a widely recognized structural system for steel building structures in seismic‐prone areas. These systems are designed to provide high lateral stiffness and strength but are typically characterized by low ductility and energy dissipation capacity. During severe seismic events, braces in traditional CBFs typically undergo inelastic deformation due to yielding in tension and compression, thus leading to permanent structural damage. To address these limitations, innovations such as dissipative devices offer a practical solution for achieving high stiffness, strength, and energy dissipation. These braces typically comprise an elastic component paired with a dissipative device, which can be either displacement‐ or velocity‐dependent. Among displacement‐dependent devices, the use of Friction Devices (FDs) has demonstrated a nearly perfectly plastic behaviour, effectively minimizing structural damage while dissipating energy during seismic events. Within this contest, this paper presents the design and preliminary experimental testing of an isolated brace equipped with FDs for steel CBFs. The primary objective is to assess the cyclic behaviour of the FDs, particularly focusing on the stability of the friction coefficient and the bolts' preloading forces. Several cyclic tests were performed with increasing loading rates to evaluate the influence of velocity on the hysteretic response of the system. The results demonstrated that the FDs exhibited consistent performance with stable frictional behaviour and minimal degradation over multiple cycles.