Investigation of the Seismic Behavior of Brace Frames with New Corrugated All-Steel Buckling Restrained Brace

摘要

All-steel buckling restrained brace (BRB) is a type of relatively new common bracings considering its low weight and whilst it is not required curing of mortar at the core of braces. In this study, a new form of all-steel BRB is introduced with corrugated edges of the core and the external sheath, and it was analyzed by using of finite element method. Existence of corrugated and ribbed edges led to enhance of buckling resistance. Numerical model was validated with laboratory samples, and after receiving an acceptable compliance in model behavior, the numerical models were offered. In this analysis, key parameters were size of brace section and distance of gap between the internal and external sheaths. The most appropriate size for gap between the core and external tube was determined to be 10mm. Upon specifying the non-linear modeling parameter, two cases of frame with ordinary concentrically brace and the proposed all-steel BRB were compared for three structures with 4, 8 and 12 floors using pushover and non-linear time history analysis. The results demonstrated that utilizing of the proposed BRB will lead to an increase in behavior coefficient and structure ductility as well as an alteration in performance level of tall structures from collapse prevention to life safety level.