## 1 Introduction  
The research on the steel plate shear wall started in Japan and the United States in the 1970s. In 1973, [PERSON] et al. [1] conducted the experimental study on steel shear wall for the first time. In 1991, [PERSON] and [PERSON] [2; 3; 4] carried out low-cycle load experiment on a series of small-scale models of steel plate shear wall and found that the stiffened steel plate shear wall had good hysteretic behaviors. Steel plate shear wall is a kind of structure with high resistance to lateral force, which is suitable for the development of high-rise buildings [5; 6; 7; 8]. Steel plate shear wall has been demonstrated with remarkable ability of seismic energy dissipation through the laboratory tests and aseismic implementations and have received much attention [9; 10; 11; 12; 13; 14]. In 1994, [PERSON] et al. [15] found that the frame column should not only bear the vertical load but also bear the interlaminar shear force from the steel plate through the study of 4 trusses of steel plate shear walls with 3 spans and 12 floors. In 2000, [PERSON] et al. [16] found the post-buckling strength of steel plates mainly depends on the shear strength of the frame by conducting an experimental study on the performance of thin steel plate shear walls in buildings. In 2002, [PERSON] et al. [17] introduced the combined members of steel tube and high-strength concrete as the vertical edge column of the specimen into the steel plate shear wall. Although the experimental results showed that the structure had good energy dissipation performance, slippage still occurred in the late stage of the loading. These research results show that the stress of the frame column is extremely complex under the effects of the bending moment caused by the deformation of the steel plate, the lateral and vertical load and the lateral displacement in practice. In order to avoid adverse effects on frame columns, [PERSON] et al. [18] proposed steel plate shear wall with slits in 2003. This structure has been applied in three practical projects in Japan. Subsequently, many scholars have proposed many different forms of steel plate shear walls with openings or slots and low yield point steel plate shear walls [19; 20; 21; 22; 23; 24], but these protect the columns at the expense of stiffness and bearing capacity of steel plate [25]. In 2013, [PERSON] et al. [26; 27; 28; 29] proposed a self-centering steel plate shear walls. It has the capabilities of recentering, which can concentrate the damage into the thin steel plate. The edge frames are connected by post-tensioning method. Self-centering steel plate walls can reduce time and cost of repair after earthquakes. In 2017, [PERSON] et al. [30] evaluated the role of frame elements in resisting lateral forces by considering the interaction between infill steel plate and frame elements and proposed a formula to predict the contribution of infill steel plate and edge frame to resist lateral forces. According to the above research results, we found that bearing capacity of the frame column has become the limitation on excellent performance of steel plate shear wall. As such, the PEC (Partially Encased Concrete) with high strength, stiffness and ductility is introduced into the steel plate shear wall structure so as to form the steel plate shear wall with partially encased composite (PEC-SPSW) system. The research on PEC column started late at home and abroad [31; 32], [PERSON] et al. [33] conducted a series of studies on PEC firstly in 1998. In 2002, [PERSON] et al. [34] studied the effects of cross-sectional dimension, spacing of connection and width-to-thickness ratio of column on the failure mode of PEC columns. In 2007, [PERSON] et al. [35; 36] developed a more complex and complete PEC column model. In 2011, [PERSON] et al. [37] studied the effect of slenderness ratio on PEC columns wrapped in fiber reinforced polymer (FRP) jackets. In 2012, [PERSON] et al.