EXPERIMENTS ON CRESCENT SHAPED BRACE, A NEW SIMPLE HYSTERETIC BRACING DEVICE

Over the last fifty years, extensive researches have been conducted in the field of seismic isolation systems, innovative earthquake resisting systems and supplemental damping, showing a potential step towards the boosting of the seismic performance of buildings. The Crescent Shaped Braces (CSB) is a new simple steel hysteretic device, recently proposed by some of the authors to be used as an enhanced diagonal brace in framed structures, within the Performance Based Design framework. By making use of CSBs as lateral resisting system, thanks to the peculiar shape of such devices, the seismic design may be optimized due to the uncoupling of its lateral stiffness from its yield strength. In the present study, the main results of experimental tests conducted on scaled CSB specimens (designed according to simplified design formulas developed by the authors) realized with different cross-sections are presented. Both monotonic pseudo-static tests and cyclic tests have been performed in order to further assess the seismic behavior of such devices. The overall experimental response in terms of stiffness, strength, ductility and global instability is compared with the design formulations, while the detailed hysteretic response is compared with the results of numerical simulations developed with commercial software. It is shown that the overall experimental behavior of CSBs is well captured by the design formulas and that commercial software are suitable to simulate the hysteretic response of such device.