Overall Stability Analysis of Improved Buckling Restrained Braces

In order to improve the behavior of double-tube buckling restrained braces (BRBs), it is proposed to set contact rings between inner tube and outer tube of the brace. As a result, they can provide lateral constraint for the inner tube; this is the improved buckling restrained braces (IBRBs). In this paper, a program was edited by the language of MATLAB based on theoretical model formulation of IBRBs and applied to the calculation of overall stability strength capacity. Finite element models of IBRBs were carried out and both load displacement curves and strength capacity were obtained. Tests on IBRBs were also conducted. The results of numerical simulation agreed with the ones of the program and tests. It indicated that the program was reasonable so it could provide a basis for the analysis of overall stability strength capacity of these kinds of IBRBs.