Numerical Assessment of Ultra-Low Cycle Fatigue Performance of Buckling Restrained Aluminum Shear Yielding Dampers

Long period seismic ground motions are known to cause large amplitude cyclic deformation in the energy dissipation devices installed in high-rise structures. Low cycle fatigue damage due to the large amplitude cyclic deformation in energy dissipation devices is of great concern. In this study, ultra-low cycle fatigue performance of buckling restrained aluminum shear yielding dampers (BR-AlSYDs) is assessed through numerical investigation on finite element program ABAQUS. Material properties of annealed Al-6063 alloy shear yielding devices are calibrated using ABAQUS platform against the cyclic experiment results. These calibrated material properties are adopted to design and investigate the BR-AlSYDs for their low cycle fatigue performance numerically. Two geometrical profiles of energy dissipator core plates are adopted in BR-AlSYD specimens which are hourglass and rectangular shapes. It is observed that the hourglass shaped energy dissipator core plates show better low cycle fatigue performance than rectangular shaped energy dissipator core plates. Further, fatigue performance parameters of Coffin-Manson relation are calibrated for BR-AlSYDs and accordingly Miner’s rule is proposed to assess the fatigue performance of these dampers for any random seismic excitation.