Design method of the pinned external integrated buckling-restrained braces with extended core. Part II: finite element numerical verification

The theoretical derivation from Part I (Jiang et al., 2015) has obtained the core contact force and the bending moment distribution of the external member in the single-wave core deformation mode. In addition, the design criteria of the external member and the strengthened core region (SCR) have also been obtained based on the understanding of the mechanical characteristics of the buckling-restrained brace (BRB). Based on the theoretical results from Part I, this study conducts the corresponding finite element (FE) numerical verification, and the BRB parameter analysis is also performed when the core deforms as a single-wave deformation. The influence of nine parameters on the core contact force and the external member stress is investigated. These parameters include the flexural rigidity of external member, the initial imperfection of external member, the core thickness and its width-to-thickness ratio, the pinned connector length, the external member length, the length of restrained strengthened core region with uniform section and the height of the wing-plate of the SCR, as well as the gap between the core and the external member. Lastly, the 12 examples of BRBs that are designed according to the proposed design criteria are analyzed using FE simulation, and the reliability of the theoretical derivation is also verified.