Buckling‐restrained braces (BRBs) are widely used as energy‐dissipation members in seismic areas, and BRBs with 10–20 m workpoint lengths have been applied in practice, particularly in tall buildings and spatial structures. This paper investigates the adverse effects of the core yield length on the compressive overstrength factor, local compressive and tensile strains, and fatigue demands. Sets of 2D shell and 3D solid models were analyzed using Abaqus, considering core yield lengths of up to 14 m and LY100, LY225, SN400B, SN490B, SA440B, and SA700 steel grades. Higher‐mode buckling and friction were shown to significantly amplify the compressive strain at the core ends and tensile strain at midspan, in part due to cyclic strain ratcheting, introducing the potential for core binding and premature necking. From these results, simple equations were proposed to calculate the compressive overstrength factor and to select the larger strong axis debonding gap and smaller design strain required for long BRBs.

中文翻译：

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长而大型屈曲约束牙套的高模屈曲和摩擦

屈曲约束支撑（BRB）被广泛用作地震区的能量消散构件，并且在实践中已经应用了工作点长度为10–20 m的BRB，特别是在高层建筑和空间结构中。本文研究了芯屈服长度对压缩超强度因子，局部压缩应变和拉伸应变以及疲劳需求的不利影响。考虑到高达14 m的核心屈服长度以及LY100，LY225，SN400B，SN490B，SA440B和SA700钢种，使用Abaqus分析了2D壳体和3D实体模型集。高模屈曲和摩擦力会显着放大芯端的压缩应变和中跨的拉伸应变，这在一定程度上是由于周期性应变棘轮引起的，这可能导致芯粘结和过早缩颈。根据这些结果，