Shake‐Table Tests of a Low‐Prestressed Self‐Centering Braced Frame

Rapid functional recovery and minimal structural damage have become critical objectives in modern seismic design. To address this need, a Low‐Prestressed Self‐Centering (LPSC) brace was developed, providing reliable re‐centering capacity with a low level of prestressing force. This study evaluates its structure‐level seismic performance through shake‐table tests on a 1/3‐scale, two‐story LPSC Braced Frame (LPSC‐BF). The test building featured hinged column bases with pinned beam‐to‐column joints in one direction, and rotational‐restrained column bases with shear beam‐to‐column joints in the other. A total of 60 tests, including unidirectional and bidirectional excitations of varying intensities, were conducted. The test building consistently achieved immediate occupancy performance, with plastic deformations confined to the steel dissipaters in the LPSC braces. These steel dissipaters were easily replaceable, enabling rapid post‐earthquake repair. Despite a minor loss in prestressing force, the residual drift remained minimal throughout testing. The direction with hinged column bases exhibited a uniform drift distribution, whereas the direction with rotationally restrained bases showed a concentration of drift at the first story. Floor acceleration responses were generally lower than the code‐predicted values. Overall, the test results demonstrate that the LPSC‐BF is an attractive seismic resilient structural system.