## 1 Introduction  
Recently, the demand for high-rise buildings to increase the spatial efficiency of cities has risen. To ensure the structural stability of high-rise buildings, it is necessary to pay particular attention to the horizontal load of the structures. Almost all exterior materials in high-rise buildings consist of glass facades. Nevertheless, glass facade laws and standards focus on wind pressure resistance and usability factors, such as insulation, watertightness, and airtightness performance. In particular, non-structural elements of buildings cause secondary damage, including the fallout of curtain wall glass facades, due to disasters such as earthquakes. However, research on the development of seismic technology for earthquakes of non-structural elements is extremely rare. Thus, research on this topic is necessary [1, 2, 3, 4]. In the case of exterior materials, unlike the structural design of major structural members, it is difficult to consider, at the design stage, the damage to the curtain wall structure due to horizontal loads caused by earthquakes [5, 6, 7]. Because the curtain wall structure is an integral structure that is generally made of prefabricated members, when an external force is applied, complex drift occurs due to various factors occurring at the joint between the members. The evaluation of structural and energy performance for curtain walls consisting of facades has been studied [8, 9, 10, 11, 12, 13, 14]. However, most of the studies related to structural performance evaluation of non-structural materials are concerned with the evaluation of damage caused by wind loads, and few experimental or analytical studies have been conducted on seismic loads [15; 16]. In addition, there has been little development of seismic reinforced curtain wall products in response to earthquakes. The conventional curtain wall structures are installed using embedded hardware in the main structure of the building, and the glass exterior material is integrated into the structure using simple bolting or welding by fasteners. As described above, the external force applied to the exterior material cannot be absorbed, so the received external force is transmitted. At this time, as the structure is deformed, damage such as breakages and bolt dropouts may occur, causing significant damage to the curtain wall exterior material, and potentially resulting in a falling facade. Reinforcement of the seismic performance of curtain walls has been conducted using the methods shown in Table 1, and the structural performance verification of seismic curtain walls has been conducted using finite element analysis [17; 18; 19; 20; 21]. In South Korea, where the frequency and magnitude of earthquakes are increasing, it is necessary to develop curtain walls that meet the dynamic seismic performance standards during earthquakes for curtain wall exterior materials, which are non-structural elements of buildings. An earthquake with a local magnitude (ML) of 5.8 occurred on 12 September 2016 near Gyeongju, South Korea. This earthquake was the largest event in Korea since 1978. Following the Gyeongju earthquake, an earthquake with a local magnitude (ML) of 5.4 occurred on 15 November 2017 near Pohang [22; 23]. Subsequently, seismic design and seismic reinforcement technology were applied to major structural members of buildings against earthquakes. However, the curtain walls, which are non-structural elements, were not sufficiently considered for seismic performance. These curtain walls are deformed when an earthquake occurs, and there is a concern that secondary damage to people and property may occur due to falling glass, or accessories may be damaged due to vibration [24; 25]. Due to this problem, studies on seismic design and reinforcement of non-structural elements, such as curtain walls and windows, have recently been conducted in Korea, and related standards are being improved. Nonetheless, the level remains insufficient [26; 27; 28].