OUT-OF-PLANE STABILITY FACTORS FOR DIAGONALLY INSTALLED BUCKLING RESTRAINED BRACES

Abstract

Buckling restrained braces (BRBs) are widely used in seismic regions as ductile seismic-resistant and energy dissipating structural members. On the other hand, the risk of overall flexural buckling under cyclic axial loading with initial out-of-plane drifts simulating the bi-directional effects of a ground motion has been pointed out. In this regard, series of formula for securing the BRB out-of-plane stability has been proposed in previous studies. However, the actual ranges of each index that make up this series of formula are not clear for practical engineers. In this paper, these index values are clarified by carrying out the research studies of various BRBs and their connections that have been used in actual design. Based on these results, a simple method that can evaluate the out-of-plane stability condition of BRBs with various connection conditions is proposed.