Adjustable stator blade damping measurement optimization method

Abstract

The invention provides an adjustable stator blade damping measurement optimization method. The method comprises the following steps: step S01, preparing a test fixture and a stator blade; s02, starting a vibration table system, determining damping parameters of the stator blade, and obtaining a damping curve of the stator blade under the gap; s03, the step S01 and the step S02 are repeated, and damping curves of the stator blade under different gaps are obtained; step S04, determining a vibration quantity value range, and calculating the area of each damping curve in the vibration quantity value range; and step S05, selecting the gap corresponding to the maximum area in the step S04 as the mounting gap of the stator blade. According to the method, accurate measurement and optimization of the adjustable stator blade damping parameters are achieved, the problems that a traditional direct measurement result is inaccurate, and the comprehensive damping effect is difficult to quantify are solved, a reliable method support is provided for damping optimization of similar components in the engine development process, and the method has remarkable engineering application value.

Description

Technical Field

[0001] This invention relates to the field of engine testing technology, and specifically to an optimized method for measuring adjustable stator blade damping. Background Technology

[0002] With the rapid development of power equipment, the hazards of vibration in various components during testing are becoming increasingly serious. Over long periods of operation, fatigue can easily occur, leading to cracks or fractures. Damping technology is a highly effective means to reduce the damage caused by vibration. Damping generally refers to the ability of a material to dissipate mechanical vibration energy as heat energy during vibration deformation; that is, the ratio of energy lost to input energy. Proper application of damping can significantly improve the vibration resistance of engineering projects, providing strong support for troubleshooting and dynamic design. At the same time, damping design is one of the most challenging design tasks in engineering. How to better leverage the positive effects of damping is a problem that urgently needs to be solved in current power equipment development.

[0003] Stator blades are crucial components in engine development and play a vital role in testing. During testing, stator blades vibrate under the excitation of factors such as airflow. Over prolonged testing, stator blades are prone to vibration fatigue, leading to cracks or fractures and ultimately, failure. Summary of the Invention

[0004] In view of this, the present invention provides an adjustable stator blade damping measurement optimization method to achieve the purpose of damping measurement optimization.

[0005] This invention provides the following technical solution: an optimized method for measuring the damping of an adjustable stator blade, comprising the following steps: Step S01, preparing a test fixture and a stator blade; Step S02, turning on the vibration table system and determining the damping parameters of the stator blade, and obtaining the damping curve of the stator blade under the given gap; Step S03, repeating steps S01 and S02 to obtain the damping curves of the stator blade under different gaps; Step S04, determining the range of vibration values ​​and calculating the area of ​​each damping curve within the range of vibration values; Step S05, selecting the gap corresponding to the maximum area in S04 as the installation gap of the stator blade.

[0006] Compared with the prior art, the beneficial effects that can be achieved by at least one of the above-mentioned technical solutions adopted by the present invention include: the present invention realizes the accurate measurement and optimization of the damping parameters of the adjustable stator blade, overcomes the problem that the traditional direct measurement results are inaccurate and difficult to quantify the comprehensive damping effect, provides reliable method support for the damping optimization of similar components in the engine development process, and has significant engineering application value. Attached Figure Description

[0007] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0008] Figure 1 This is a flowchart illustrating an embodiment of the present invention; Figure 2 This is a schematic diagram of the damping parameter measurement curve; Figure 3 This is a schematic diagram of the damping measurement screening curve. Detailed Implementation

[0009] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0010] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0011] like Figure 1 As shown, the adjustable stator blade damping measurement optimization method of the present invention aims to optimize the damping effect of the stator blade by precisely controlling the test conditions, scientifically measuring the damping parameters, and systematically screening the optimal clearance. This provides reliable data support for the structural design optimization and fault diagnosis of engine stator blades, effectively improves the vibration resistance of the stator blades, and reduces the risk of cracks or fractures caused by vibration fatigue.

[0012] Step S01: Prepare the test fixture and stator blades.

[0013] The core of this step is to build a test platform that meets the test requirements, ensuring that the test conditions are consistent with the actual working state of the stator blades on the engine, thus laying the foundation for the accuracy of subsequent damping parameter measurements.

[0014] The specific implementation process is as follows: Select a test fixture suitable for the stator blade to be tested. The structural design of the test fixture must meet the requirements of simulating the installation state of the stator blade on the engine. Connect the test fixture to one end of the stator blade using a fixed constraint method to ensure a firm and secure connection. The other end is equipped with an adjustable clearance structure, which allows for precise adjustment of the clearance between the stator blade and the fixture. The clearance adjustment range must cover the clearance range that the stator blade may encounter during actual operation.

[0015] The test fixture with the stator blades installed is mounted on the vibration table slide. During the installation process, the connection stability between the test fixture and the vibration table slide must be ensured. The installation torque must be strictly in accordance with the engine test installation torque to avoid distortion of test results due to deviation in installation torque.

[0016] Strain gauges are installed at the nodal line of the stator blade. The nodal line is a region highly sensitive to strain response during stator blade vibration; installing strain gauges at this location allows for accurate capture of the stator blade's vibration signals. After installation, the strain gauges are connected to the vibration testing system, data acquisition system, and other testing systems. During connection, it is essential to ensure good wiring contact and avoid signal transmission interference.

[0017] Step S02: Turn on the vibration table system and determine the damping parameters of the stator blade, and obtain the damping curve of the stator blade under this gap.

[0018] This step involves exciting the stator blades using a vibration table system, obtaining damping parameters using professional measurement methods, and then plotting the damping curve to provide basic data for subsequent clearance optimization and selection.

[0019] The specific implementation process is as follows: Start the vibration table system and set the sweep frequency range of the vibration table, which must cover the possible natural frequency range of the stator blade. Perform frequency sweep excitation through the vibration table, and use the connected strain gauges to collect the strain signals of the stator blade at different frequencies. After processing by the data acquisition system, determine the natural frequency f0 of the stator blade.

[0020] The excitation frequency of the vibration table is fixed at the natural frequency f0 obtained above, and a set excitation force is applied. This excitation force needs to be selected within the range of excitation forces that the stator blade will bear during operation. Under the conditions of set gap and set excitation force, the stator blade is continuously excited, and the vibration response signal of the stator blade is collected by strain gauges. The frequency response curve under this condition is obtained in combination with the test system.

[0021] like Figure 2 As shown, the frequency response curve above is analyzed using the half-power bandwidth method, and the damping parameter δ under this condition is calculated. n The formula for calculating the half-power bandwidth method is as follows: , where δ n Here, f1 represents the first frequency corresponding to the half-power point in the frequency response curve, f0 represents the natural frequency of the stator blade, and f2 represents the second frequency corresponding to the half-power point in the frequency response curve. This formula allows for the accurate calculation of the stator blade's damping capacity under the current operating conditions.

[0022] Keeping the set gap constant, gradually change the magnitude of the excitation force according to the preset step size, and repeat the above steps to obtain the damping parameter δ corresponding to at least 20 different excitation forces.n Plotting the excitation force as the abscissa and the damping parameter δ... n Using the vertical axis as the ordinate, all measured coordinate points are fitted to obtain the damping curve of the stator blade under this gap.

[0023] Step S03: Repeat steps S01 and S02 to obtain the damping curves of the stator blades under different clearances.

[0024] To fully investigate the effect of the gap on the damping effect of the stator blade, it is necessary to repeat the above experimental process by changing the gap size and obtain multiple sets of damping curves.

[0025] The specific implementation process is as follows: The adjustable gap structure of the test fixture is used to adjust the gap between the stator blade and the fixture. The gap is adjusted one by one in descending order, and the gap size must be ensured to be stable and accurate after each adjustment. For each adjusted gap, the installation and fixing, strain gauge connection in step S01 and the frequency sweep, excitation, damping parameter measurement and damping curve plotting operations in step S02 are repeated. Finally, the damping curves of the stator blade corresponding to different gaps are obtained, forming multiple sets of damping curve data.

[0026] Step S04: Determine the range of vibration values ​​and calculate the area of ​​each damping curve within the range of vibration values.

[0027] This step involves defining the range of vibration values ​​relevant to actual work and calculating the integral area of ​​the damping curve within that range, thereby enabling a quantitative evaluation of the damping effect under different clearances.

[0028] The specific implementation process is as follows: like Figure 3 As shown, based on the actual operating conditions of the engine, the range of vibration values ​​that the stator blades experience during operation is determined. The endpoints of this range are denoted as A1 (minimum value) and A2 (maximum value), respectively. This range must fully cover the vibration value interval of the stator blades from idle to maximum engine speed. In the figure, A represents the vibration value.

[0029] For each damping curve obtained in step S03, an integral calculation method is used to calculate the area enclosed by the damping curve and the horizontal axis (vibration value) within the vibration value range [A1, A2]. The area calculation uses the formula... Where S is the area of ​​the damping curve within the range of vibration magnitude, δ n As the damping parameter, the integral result intuitively reflects the comprehensive damping effect of the stator blade within the actual working vibration range under the corresponding gap.

[0030] Step S05: Select the gap corresponding to the maximum area in S04 as the installation gap of the stator blade.

[0031] By comparing the comprehensive damping effects of different gaps, the optimal installation gap is selected, providing a basis for the actual installation and application of stator blades.

[0032] The specific implementation process is as follows: Compare and analyze all the area values ​​calculated in step S04 to find the maximum area. The gap corresponding to the damping curve of this maximum area is the gap that enables the stator blade to achieve the optimal comprehensive damping effect within the actual working vibration range. Determining this gap as the optimal installation gap for the stator blade and applying it to the stator blade installation design can maximize the stator blade's vibration resistance and reduce the risk of vibration fatigue failure.

[0033] Through the above specific implementation methods, the present invention achieves accurate measurement and optimization of the damping parameters of adjustable stator blades, overcoming the problems of inaccurate traditional direct measurement results and difficulty in quantifying the comprehensive damping effect. It provides reliable methodological support for the damping optimization of similar components in engine development and has significant engineering application value.

[0034] The above description is merely a specific embodiment of the present invention and should not be construed as limiting the scope of the invention. Therefore, any substitution of equivalent components or equivalent changes and modifications made within the scope of protection of this patent should still fall within the scope of this patent. Furthermore, the technical features, technical features and technical solutions, and technical solutions in this invention can be freely combined and used.

Claims

1. A method for optimizing the measurement of adjustable stator blade damping, characterized in that, Includes the following steps: Step S01: Prepare the test fixture and stator blades; Step S02: Turn on the vibration table system and determine the damping parameters of the stator blade, and obtain the damping curve of the stator blade under this gap. Step S03: Repeat steps S01 and S02 to obtain the damping curves of the stator blades under different clearances. Step S04: Determine the range of vibration values ​​and calculate the area of ​​each damping curve within the range of vibration values; Step S05: Select the gap corresponding to the maximum area in S04 as the installation gap of the stator blade.

2. The method for optimizing the measurement of adjustable stator blade damping according to claim 1, characterized in that, Step S01 is as follows: The test fixture is fixed and constrained to one end of the stator blade, and an adjustable gap is provided at the other end. Install the test fixture on the vibration table slide, install strain gauges at the connection points of the stator blades, and connect the various test systems.

3. The method for optimizing the measurement of adjustable stator blade damping according to claim 2, characterized in that, Step S02 is as follows: Turn on the vibration table system and obtain the natural frequency of the stator blade by frequency sweeping; The frequency response curves were obtained under the conditions of set gap and set excitation force by performing excitation operation at the natural frequency. Damping parameters were determined using the half-power bandwidth method. By changing the excitation force, the damping parameters under different excitation forces are obtained, and the damping curve of the stator blade under the gap is plotted.

4. The method for optimizing the measurement of adjustable stator blade damping according to claim 3, characterized in that, Half-power bandwidth method is ,in, For the corresponding damping parameters, For the first frequency, Based on the base frequency, This is the second frequency.

5. The method for optimizing the measurement of adjustable stator blade damping according to claim 4, characterized in that, Step S04 specifically involves: using the formula Calculate the area of ​​each damping curve within the range of vibration values, where A1 and A2 are the endpoint values ​​of the range of vibration values.

6. The method for optimizing the measurement of adjustable stator blade damping according to claim 3, characterized in that, The specific steps in step S02 for obtaining damping parameters under different excitation forces are as follows: obtain at least 20 damping parameters under different excitation forces.

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