## 2 Experimental Configuration
### Experimental Scheme and Contents  
Regarding the structure of the compressor static blade, it is a component that is fixed to the cylinder by the assembly structure. To summarize the traditional method, there are roughly four types of assembly for static blade rings. These are the cantilever type, assembled type, welded type and adjustable type. Because an increase in the structure connected with compressor stator blade brings more contact friction, its vibration law is more difficult to describe accurately. In this case, it is of great significance to analyze the nonlinear vibration of blades accompanied by contact friction. In real compressor equipment, the structure of the stator blade is very complicated. Therefore, the simulation and analysis of the vibration characteristics of stator blades under contact friction in experimental conditions need to be reasonably simplified. The purpose of the test bench constructed in this study is to measure the stator blade vibration response curve under a specific exciting force when the test blade and the outer holding ring have contact friction characteristics. The selected parameters are based on relevant studies in reference [25]. In order to enhance the stability of the test process, there are some restrictions on the selection of the parameter range for this test bench. First of all, the normal load of the contact surface cannot be too large; otherwise, there is no relative movement of the contact surface, which makes the overall model approximate to a linear system. Secondly, corresponding to a certain value of normal load on the contact surface, too large an exciting force will exceed the range of friction damping and lead to blade sliding. The test system built in this paper can be used to measure and analyze the blade vibration response with different normal forces of the contact surfaces and different amplitude and frequency excitation forces. Figure 5 gives the main steps in the experimental measurement. The specific test steps are as follows:  
1. Install the blades and inner and outer rings, and stably connect each part of the structure to the outer steel frame through bolts. Install the exciting force application  
Figure 5: Main flow chart of the test measurement. device and adjust the direction of the exciting rod to be perpendicular to the blade surface. Arrange the eddy current displacement sensor and connect the data collector. Check the fixed condition of each structure to ensure the stability of the test process. 2. Determine the normal load according to the working condition requirements of numerical analysis. The adjusting bolt at the contact surface is controlled by the torque wrench, and the normal force on the contact surface between the stator blade and the outer holding ring is set using this method. 3. Adjust the signal generator and power amplifier according to the requirements of numerical analysis. An exciting force of a certain amplitude and a certain frequency is applied to the blade surface. 4. Measure the vibration response at the bottom of the blade using the eddy current displacement sensor to obtain the vibration response under a certain contact surface normal load and excitation amplitude. 5. Replace the excitation amplitude and repeat Steps 3-4. A response curve of the test model blade with different amplitudes of excitation force is obtained. 6. Adjust the normal force on the contact surface using a torque wrench and repeat Steps 2-5 to measure the blade displacement. A response curve of test model blade with different contact surface normal loads is obtained. 7. According to the measured data of several research conditions, analyze the vibration laws for compressor stator ring under the action of contact friction. It should be noted here that in order to make the response amplitude of the model blade more obvious during this experiment, the direction of action of the exciter is the circumferential direction of the blade.