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Higher‐mode buckling and friction in long and large‐scale buckling‐restrained braces
Author(s) -
Sitler Ben,
Takeuchi Toru
Publication year - 2021
Publication title -
the structural design of tall and special buildings
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.895
H-Index - 43
eISSN - 1541-7808
pISSN - 1541-7794
DOI - 10.1002/tal.1812
Subject(s) - buckling , structural engineering , necking , ultimate tensile strength , dissipation , core (optical fiber) , materials science , yield (engineering) , strain (injury) , compressive strength , composite material , engineering , physics , medicine , thermodynamics
Summary 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.