Flexural Demand on Pin-Connected Buckling-Restrained Braces and Design Recommendations

AbstractIn a previous study by the authors, the cyclic behavior of a novel type of pin-connected angle steel buckling-restrained brace (ABRB) was examined, and the failure mechanism in the core projection of the ABRB induced by an excessive bending effect caused by end rotation was discussed. In this paper, the occurrence mechanism of end rotation modes and the bending effect in the core projection of an ABRB are first investigated based on the previous test results, which shows that end rotation demands would be significantly increased with the presence of a gap and an additional bending effect could be observed if the end rotation demands were large enough to cause two-point contact at the core ends. Then, a new method to predict the flexural demand on pin-connected BRBs is proposed by considering the effect of the end rotation modes, clearance, initial eccentricity, and initial deflection of casing. The design criteria to prevent yielding of the core projection are presented and further verified by the...