Seismic performance and replaceability evaluation of multi-section energy-consuming beams

A multi-section replaceable energy-dissipating beam (MRB) is developed for a hybrid frame structure with energy-dissipation frames (HF-EDFs), which is designed to satisfy the space requirements and ensure excellent seismic resilience. Firstly, the working mechanism of MRBs in the HF-EDFs is presented. Subsequently, four specimens are designed and tested by cyclic loading to evaluate the seismic behavior and replaceability. Experimental results show that MRBs failed as a shear mechanism, in contrast to the single-section beam with the same length which failed as a shear-bending mechanism. MRBs behaved superior in loading-carrying, energy-consuming, and deformability. Reduction in length ratio and use of low yield point steels could increase the seismic performance. Replaceability analysis indicates that the replacement process of MRBs is convenient, and does not affect the force performance of the structure. The residual inter-layer drift ratio theta re and residual rotation at the beam end phi re for the specimens could meet the replacement under the design earthquake action. Furthermore, a finite element analysis with different length ratios was conducted. Results indicate that the overstrength and the energy dissipation capacity improve with the length ratio decreases. Finally, a recommendation for the length of the energy-dissipating beam segment is given to satisfy the replacement requirement based on the experimental and numerical data.