Investigation of global and local stability of buckling restrained braces

In this study, the Buckling Restrained Braces (BRBs) with different casing systems were investigated experimentally. Buckling restrained braces (BRBs) have high energy dissipation capacity and equal tension and compression axial load capacity. Therefore, the application of BRBs has gained popularity in seismic regions. The first studies on BRBs started in Japan in 1970 and since then more studies have been undertaken in other earthquake prone countries. The BRBs consist of core plate (CP) and casing member (CM). The CM prevents the CP from buckling. Hence, the CP can yield under tension and compression demands. The component tests for four BRBs were performed in order to exam the different casing systems namely steel tube-concrete, confined and unconfined concrete and built-up sections. In unbounded steel tube-concrete BRB, steel hollow sections were attached on the restrained elastic and plastic part on the CP to prevent the local buckling. The built-up section were consisted of four steel hollow sections connected to each other via batten plates. The confined and unconfined concrete were used for CM of BRBs to obtain economical and practical casing systems. This study presents experimental investigation of buckling restrained braces (BRBs) with different casing systems. The main parameters investigated during the member based BRB tests were casing system, gap material and gap between core plate and casing. The component tests for four BRBs were performed in order to exam the different casing systems namely steel tube-concrete, confined and unconfined concrete and built-up sections. In unbounded steel tube-concrete BRB, steel hollow sections were attached on the restrained elastic and plastic part on the CP to prevent the local buckling. The built-up section were consisted of four steel hollow sections connected to each other via batten plates. The confined and unconfined concrete were used for CM of BRBs to obtain economical and practical casing systems. An economic solution was proposed to use as a ready-rolled profile Core Plate(CP). Furthermore, the connection details namely slip critical, isolation materials, and their application techniques have also been investigated for the improved BRB design in this study.