## 4 Conclusions  
Cyclic quasi-static tests were performed on eight replaceable links with different parameters in EBF. The seismic behavior and damage modes of specimens were analyzed. As the replaceable links are separated from the frame beams, inelastic deformation is concentrated in the shear link during a severe earthquake; therefore, damaged links can be easily replaced. Based on the results, the following conclusions were drawn:  
1. The failure mode of specimens without welding access holes was brittle failure of the link flange-to-end plate weld that cracked, which was caused by the distribution of complex residual stress at the welds of the end plate. Owing to the welding access hole adopted in links, stress distribution of the web was more uniform, and the failure modes of specimens were ductile failure.
2. Stress distribution of the web was more uniform for links with the welding access hole than for links without the welding access hole, and the effect of the stiffener of specimens after shear yielding was not obvious. Link damage is caused by the incessant interactive actions of the plastic development and deformation, and it is possible to focus the structure's inelasticity on the link.
3. The hysteresis curves of the replaceable links with welding access holes were stable and the inelastic deformation of the structure could be concentrated in the links. The link was treated using welding access holes that had a prominent effect on the improvement of seismic behavior.
4. The energy dissipation capacity of the specimen was mainly dependent on the arrangement of stiffeners and the welding access holes. When the dimensions and lengths of the specimens were the same, the energy dissipation capacity of the specimen with relatively closer stiffener spacing was better. The energy dissipation capacity of the specimen with welding access holes was better than that of specimens without welding access holes, where welding access holes relieved stress distribution.  
* Welding access holes effectively enhanced the plastic deformation capacity of the links, where the minimum plastic rotation angle of the specimen was 0.10 rad and the maximum was 0.16 rad. As the section dimension and length of the link were the same, the stiffener spacing had the same remarkable effect on the plastic deformation capacity of the link.
* The stiffener spacing, the welding access holes, and the length ratio \(\zeta\) had a remarkable effect on the bearing capacity of the links. The bearing capacity of the specimen with welding access holes was better than the other specimens. The smaller the length ratio \(\zeta\) the larger the bearing capacity would be. The length ratio \(\zeta\) had a great influence on the initial stiffness of the link.
* The stiffness degradation of the link was mainly dependent on the length ratio \(\zeta\). As the length and the stiffener spacing were the same, the smaller the length ratio \(\zeta\) of the specimen, the more obvious the stiffness degradation.
* In our future work, we will explore the use of PZT patches and the active sensing method to quickly evaluate structural integrity by detecting cracks and bolt loosening after a seismic event.  
[PERSON] designed the experiments. [PERSON] performed the experiments. [PERSON], [PERSON], and [PERSON] analyzed the data and wrote the paper.  
This research was supported in part by the National NSFC (Natural Science Foundation of China) (51368037, 51568040), the Basic Research Foundation of Colleges, and the Universities of Gansu Province.  
The research presented in this paper is part of Project (51368037, 51568040) supported by National Natural Science Foundation of China. In addition, authors would like to acknowledge the support from Lanzhou University of Technology in China experimental equipment for this research and Ningxia University for providing technical consultation.  
The authors declare no conflict of interest.