## 1 Introduction  
Structures have always been designed to meet the collapse prevention requirements under rare earthquakes; however, due to excessive local or overall deformation, the majority of existing structures are no longer suitable for further use and need to be rebuilt at a lower cost compared to the repair, and the shape memory alloy has been applied to structures for self-centering, which is a frontier issue for further research [1, 2]. The links in traditional eccentrically braced steel frames performing as a fuse are initially damaged, which may affect the overall stability of the structure, causing the fracture of the connected beam [3, 4, 5]; furthermore, the links could suffer more complicated repairs even when the beam remains intact. To solve the complicated repair problem of the link, increasingly more research scholars have proposed replaceable designs rather than additional collapse-resistant designs in recent years. [PERSON] et al. [6, 7] proposed the application of high-strength steel in seismic-resistant structures. [PERSON] and [PERSON] [8, 9, 10, 11, 12, 13] proposed an end-plate connection and bolted web-connected replaceable link, and they used them in the high-strength-steel framed-tube structures; furthermore, the cyclic behavior and seismic performance of the replaceable link were analyzed by experiment and finite element analysis with the design method. Moreover, [PERSON] [14, 15, 16, 17] projected the vertical link in the eccentrically braced steel framesand researched the seismic performance by experiment and finite element analysis, and they proposed replaceable links in eccentrically braced steel frames after earthquakes. In addition, the replaceable links can be easily replaced or repaired by fixing the bolt along the end-plate or web, because the vertical link in the structures is not connected to the floor and isolated to the beam. In this paper, a new type of variable-cross-section replaceable link that can be quickly repaired is proposed in a high-strength eccentrically braced steel frame. In order to ensure the elastic design of the non-energy-dissipation components, during the design process of the eccentrically braced frame, the beams, columns, and braces are designed with an enlarged elastic internal force, which refers to the internal force of the beam, column, and brace when the link reaches the plastic shear bearing capacity. The plastic deformation is naturally isolated in the links, while the rest of the structure remains elastic, thus ensuring that the seismic energy is concentrated on the replaceable link. The frame beams and columns made of high-strength steel (\(f_{y}\geq 460\) MPa) are shown in Figure 1. The sufficient elastic deformation capacity of high-strength steel makes the non-energy-dissipating members of the structure capable of recovering elastic deformation after an earthquake. The cross-section of the frame beams and columns will be large when using ordinary steel; however, the application of high-strength steel will improve the behavior and lower the self-weight, saving steel consumption while reducing the seismic effect and the cost of the foundation. Meanwhile, the residual deformation of the structure is minimal due to the large axial stiffness of the braces. The structure proposed in this paper integrates the advantages of the wider-ranging elastic deformation of high-strength steel and the greater lateral stiffness of the eccentric braces, as well as the better energy dissipation capacity of the new replaceable link. The cross-section of the variable replaceable link can be optimized and designed without considering the section of the frame beam, and it would achieve better economic benefits. The new variable-cross-section replaceable link consists of three parts: an energy-consuming region, bolts connection parts, and variable section.