Subassemblage test of buckling-restrained braces with H-shaped steel core

In this study, a subassemblage test was performed using buckling-restrained braces with an H-shaped core element, which have been proven in a previous uniaxial component test to have good performance. The loading protocol prescribed the quasi-static cyclic pattern with stepwise incremental displacement amplitude. Two different end connections (bolted connection and pin connection) and two different buckling-restrained mechanisms (concrete-filled tube and hollow steel tube) were examined as the test parameters. The performance of the specimen was evaluated by comparing the test results with the recommended provisions for buckling-restrained braces. The test results showed that the compression strength capacity of buckling-restrained brace (BRB) with in-filled concrete increased by about 10% compared with BRB without in-filled concrete. According to test result at same story drift of 2D_bm, structural performance of pin connection specimen without bolt slippage is superior to bolted connection specimen. Also, bolted connection specimens showed similar performance for total energy dissipation and cumulative plastic ductility, regardless of the connection types and the existence of concrete filling.