Seismic performance study on prefabricated self-centering rocking steel frame

To reduce the damage of the traditional steel frames under strong earthquakes, a type of prefabricated steel frame structure with self-centering rocking column footings was proposed. The construction details and working mechanism of the frame were introduced. A rocking steel frame with a scale ratio of 1/4 was designed and manufactured. The low-cycle reversed loading tests and finite element simulation were carried out on the specimen to investigate its seismic performance. The research results show that the rocking steel frame realizes the controllable rocking of the column footings under strong earthquakes based on composite combination disc spring, whereas the cumulative damage and residual deformation of the frame are effectively controlled by the energy dissipation device of the beam-to-column connections. The frame exhibits relatively plump flag-shaped hysteretic loops, confirming that it possesses relatively good self-centering and energy dissipation capability. As the inter-story drift of the frame reaches the extremely rare inter-story drift ratio of 1/30, the beam-to-column connections and column bases do not show notable yielding or buckling, the main structure remains elastic and the damage is concentrated at the energy dissipation device. Moreover, the second-phase loading curves are consistent with the original loading curves after the energy dissipation device is removed and replaced by a new one, which effectively achieves the design goal that the energy dissipation device can be replaced and the structural functions can be restored after strong earthquakes. The results of finite element simulation agree well with test results, validating the established finite element model can reasonably predict the hysteretic behaviors of the rocking steel frame under cyclic loading. © 2021, Editorial Office of Journal of Building Structures. All right reserved.