Numerical modelling and analysis of buckling-restraint braces in frame buildings due to seismic loads

Abstract

Buckling-Restraint Braces (BRB) is a new type of bracing system with energy dissipation mechanisms developed to improve the behaviour of conventional braces. In this system, the bracing member is placed in a metal or concrete casting that prevents this member from experiencing failure due to the lateral buckling. By implementing these changes, the brace's behaviour in compression is identical to its behaviour in tension, which is accompanied by yielding of material and therefore buckling does not occur. In this paper, the effect of the BRB system on the seismic performance of a typical frame is evaluated using the finite element method. Numerical studies using ABAQUS software are conducted to develop a 3D model of a BRB system, considering the nonlinearity effects of material and geometrical deformation. The BRB component is analysed under the cyclic loading protocol recommended by FEMA 450 and the resultant hysteretic behaviour of BRB is compared with the experimental work. The results show that the application of this system in structures may improve the stability of the structural system and enhance the energy dissipation mechanisms in the buildings. As a result, the structural design will be safer and more economical.