## 2 WSVI Design Description  
Figure 1a,b show isometric and internal views of the proposed WSVI. This WSVI was developed to reduce the launch loads above the range of the 28 Hz target cut-off frequency for a 40 kg class satellite. The design strategy of the isolator involves implementing a high damping capability by applying a superelastic SMA blade with a multilayered thin plate with viscous lamina tapes. The SMA material can be applied because it provides superelastic characteristics, high damping capability, and fatigue durability, compared to ordinary metal materials [12]. Superelastic behavior is known to have complete re  
versibility for strains of up to 10-12% without being plastically deformed, which is a very uncommon feature in ordinary metal materials [11]. Therefore, the SMA blade makes it possible to ensure the structural safety of the low stiffness blade of the isolator under the launch environment. In addition, multilayered thin metal plates with viscous lamina tapes were utilized to increase the damping capability, which also helped distribute the stress release acting on the thin SMA blade. The proposed WSVI is mainly composed of SMA blade modules to achieve the required target cut-off frequency in the axial and lateral directions, a moving plate, upper and bottom plates, inner and outer brackets, and displacement limiters to limit the movement of the blades to within their allowable deflection range. The stiffness of the vibration isolator for each axis is significantly governed by the SMA blade modules. Figure 1: Configuration of the Proposed WSVI (**(a)** Isometric View, **(b)** Inside View). To achieve the required isolator stiffness, the SMA blade modules for the axial direction are connected between the inner and outer brackets at 120\({}^{\circ}\) intervals. The SMA blade modules for the lateral direction are arranged between the moving plate and inner bracket, in the same manner as those of the axial direction. The blade is made of superplastic SMA, and it provides a mechanical interface to attach viscoelastic adhesive tapes with thin constrained layers made of FR-4 material. Two constrained layers were applied to each side of the SMA blade. The physical contact between the constrained layers and adhesive tapes reduces the resultant stress acting on the SMA blade because the viscoelasticity resists additional deformations of the SMA blade. Furthermore, each boundary layer between the adhesive tapes and constrained layers experiences shear deformation when the multilayered SMA blade is deformed. This design contributes to the excellent damping performance and enhanced structural safety of the SMA blades. To limit the deformation of the blades within the allowable range of \(\pm\)5 mm, displacement limiters made of high damping plastic material of Delrin [18], with space heritages are included on the design, which is helpful to dissipate and mitigate launch vibration loads when slip and contact occur between the plastic and plastic materials. The mechanical properties of the SMA materials are summarized in Table 1[12]. The viscoelastic tape used in this study was 3M966 double-sided acrylic tape (3M) [19], as listed in Table 2.  
A static load test was performed at room temperature to evaluate the basic characteristics of the proposed WSVI. Two WSVI cases with different SMA blade thicknesses (1) 0.8 mm and (2) 1.5 mm were used in this test. Figure 2 shows an example of a static load test setup for the lateral axis. The WSVI was connected to the load cell using a grip and a connector, which was mounted on the upper side of the static testing machine. In addition, the Delrin parts of the WSVI were intentionally removed to check the internal status of the blades during the test. Repeated translational loadings of three cycles in the positive and negative directions were applied to the WSVI in each axis to measure its