Study on seismic performance of prefabricated self-centering steel frame: Fid-Bau Portal

Study on seismic performance of prefabricated self-centering steel frame

Yun, Chen / Chao, Chen

Abstract Unexpected plastic damage and residual drift can be usually observed in traditional rigid-connection steel frames (RCSFs) after severe earthquakes. To enhance seismic performance of the RCSFs, this paper proposes a novel prefabricated self-centering steel frame (PSCSF) that incorporates pre-pressed composite combination disc spring (CCDS) installed in the column bases to provide satisfactory re-centering capability and eliminate residual deformation along with buckling restrained braces (BRBs) set at the bottom flange of steel beam to dissipate seismic input energy and reduce structural damage. Firstly, configuration details and design methodology of the PSCSF are introduced. A quasi-static loading test was conducted on the PSCSF specimen to investigate cyclic hysteretic response of the proposed innovative frame. Secondly, finite element analyses were performed with the aid of software ABAQUS to reveal seismic mechanism of PSCSF. Finally, the restoring force model of PSCSF was established based on mechanical analyses and theoretical calculation results were compared with experimental results to validate the correctness of the proposed model. The research results indicate that the PSCSF specimen exhibits full double flag-shaped hysteresis curves subjected to cyclic loading, demonstrating that the PSCSF possesses favorable self-centering capability and desirable energy dissipation capacity as well as stable mechanical behavior for the predefined target displacement. The beam and column maintain elastic and plastic damage is confined to the BRBs during entire loading process. The simulation results agree well with the test results, demonstrating that the established finite element model can capture cyclic response of the PSCSF under cyclic loading. The theoretical results calculated by restoring force model are in good accordance with the test results, confirming that the established restoring force model can reasonably predict the hysteretic behavior of the PSCSF under low cycle reversed loading.

Graphical abstract A novel prefabricated self-centering steel frame (PSCSF) was proposed and experimentally validated in this paper. The main innovations are as follows:(1) The PRCSF utilizes controllable rocking of the column bases under the strong earthquakes to avoid plastic damage and re-center its origin position through the self-centering moment provided by CCDS. The cumulative damage and residual deformation of the PRCSF are effectively reduced by the BRBs installed at the bottom of beam flange. (2) the PRCSF exhibits elastic deformation and rigid body rotation deformation mechanism before and after the uplifting of column bases. The deformation mode conforms to the expected design concept. The double flag-shaped hysteresis curves of the frame can be found, indicating that the PRCSF is capable of satisfactory self-centering capability and desirable energy dissipation capacity. (3) The simulation results are in good agreement with the test results, demonstrating that the established finite element model can capture cyclic response of the PRCSF under cyclic loading. (4) The calculation results based on the proposed restoring force model agree well with the experimental results, conforming that the proposed restoring force model can reasonably predict the hysteretic behavior of the PRCSF and be applicable to the design guide of the PRCSF in the future works. Display Omitted

Highlights • An innovative PSCSF with enhanced seismic performance is proposed and experimentally validated. • The hysteretic behaviors of the PSCSF are investigated by low cycle reversed loading tests. • A practical analytical model of the PSCSF is established by theoretical analyses .