Development of Two Types of Buckling Restrained Braces Using Finite Element Modelling

Buckling Restrained Braces (BRBs) provide structures with large lateral deformation capacity, strength and stiffness. Throughout the years, BRBs proved to be a viable solution, based on their increasing usage as structural fuse elements. A BRB consist of a steel core introduced into a buckling restraining mechanism (BRM). The main BRB’s feature is its quasi-symmetric and stable hysteretic behaviour when cyclically loaded. In addition to normal braces, BRBs have their compressive behaviour improved by confining core’s transversal deformations, and thus restraining the core’s global buckling. Due to the fact that most BRBs are proprietary and rather manufactured than designed, design codes (P100-1/2013) require their experimental qualification. This code’s regulation represents an impediment in using the BRBs on a wider scale. To overcome these problems, a set of typical BRBs were developed with capacities corresponding to typical steel multi-storey buildings in Romania. The paper presents the pre-test numerical simulations performed. The numerical finite element model development using Abaqus 6.14 software and its calibration based on experimental data are presented in detail. The numerical study was used to develop “conventional” and “dry” solutions by analysing several different solutions. The main difference between the two is the absence of concrete in the case of “dry” solution. The cyclic performance of the BRBs was assessed in terms of compression adjustment factor and global performance.