Abstract
This paper proposes a new type of brace, named Naturally Buckling Brace (NBB), for building structural systems which significantly improves the drawbacks of braced frame systems. NBB consists of high strength steel (HSS) and low yielding steel (LYS) channels with an intended initial eccentricity along the brace length. LYS contributes to early yielding, and HSS contributes to keeping stiffness and stable behavior after LYS yielding. These effects can be also obtained by intended initial eccentricity. Tests with various design variables were conducted and subjected to cyclic loadings to examine the seismic performance of the proposed NBB. The results confirm that the proposed braces can achieve early yielding, provide a large post-yield stiffness and high ductility, which stably dissipate energy from around 0.02% story drift and prevent local buckling as well as deformation concentration until a very large story drift (greater than 3%) being reached. In addition, FEM model was built using FEM program “ABAQUS”, which shows strains in NBB are more distributed compared to those in CBB counterpart specimen.
