## 2 Experimental Configuration  
### Test Bench  
In this section, the relevant information of the test bench used in this study is introduced. Firstly, the basic composition of the test bench is briefly described, which mainly includes the following four subsystems (Figure 1 shows a brief schematic diagram of the test bench system). 1. The first part of the test system is the scaffold structure for support and fixation. During the experiment, the blade needs to be measured and the connected inner and outer rings need to be well fixed. At the same time, devices such as sensors and exciters also need to provide very stable structural support. In particular, the top face of the outer holding ring of the compressor blade is defined as a fixed constraint condition in this numerical study, so it is necessary to simulate this state as much as possible during the experiment. According to these technical requirements, there is a very large steel frame on the outside that is sufficient to provide a stable base and support. Each part of the system is connected by a bolted structure to build a whole test bench. The exciter is fixed on a platform. The side of the platform is bolted to the steel frame and the height can be adjusted. The compressor stator blades and inner and outer rings are fixed under a platform. The platform is still bolted to the steel frame and can also be adjusted in height. Figure 2 shows the actual structure of the test bench. Figure 1: Test bench system diagram: (a) signal generator, (b) power amplifier, (c) exciter, (d) compressor stator blade, (e) inner ring, (f) outer holding ring, (g) adjusting bolt, (h) blade vibration response measurement point, (i) steel frame, (j) data collector, (k) computer, (l) display screen. 2. The second part comprises the compressor stator blade and the connected inner and outer holding ring structure tested in the test. In this study, the contact friction characteristics of the blade and the outer holding ring should be considered. Therefore, a T-shaped barb-like structure was designed at the top and root of the blade. The structure is connected with the inner and outer rings, and the contact surface is provided with adjusting bolts to change the normal load. This part is the main object of the test; it is necessary to provide a detailed explanation of the structure of this part. Figure 3 shows a connection structure diagram of the blade and the inner and outer rings. The uppermost structure is a fixed platform. The platform has a bolted structure around it to attach the fixed plates and outer steel frame. In this way, the topmost platform provides a stable supporting environment for hanging the test blades. The outer ring and the top platform have two holes. Two perfectly matched metal rods are inserted to create a stable connection. The displacement of the outer ring in the horizontal and vertical directions can be limited by this connection. That is to say, this structure simulates, as closely as possible, the fixed constraints at the top of the outer ring under numerical conditions. When the outer holding ring is fixed, the blade is connected to it through the tip bar. Adjusting bolts are also installed on the contact surface to change the contact normal load. Similarly, there are inner ring connections at the root of the blade. It should be noted that there are two adjusting bolts on the sides of the inner and outer rings. The bottom structure is a support block, and it is a buffer for jacks and test pieces. Under it, a hydraulic jack is used to lift the entire test device to a suitable height. Because the weight of the test part is relatively large, the bottom needs to be lifted to a height before assembly. Of course, after the test unit is assembled, the hydraulic device at the bottom is removed. In other words, the test measures a cantilever beam structure with a fixed top. 3. The third part is the load-generating device.