An experimental test system and method for dynamic characteristics of dry friction damping

Abstract

The invention discloses an experimental testing system and method for the dynamic characteristics of dry friction damping. The experimental testing system includes: a moving plate; a piezoelectric holding device and a motion transmission mechanism are fixedly installed on the moving plate; the piezoelectric holding device and The motion transmission mechanism is connected through the piezoelectric actuator; the motion transmission mechanism is fixedly installed with the first analog piece fixture; the first simulation piece fixture is installed with the first blade root platform simulation piece; the fixed plate; the fixed plate is fixedly installed with the signal The holding device; the signal holding device is equipped with a piezoelectric force sensor; the piezoelectric force sensor is connected with the second simulation piece fixture through a force transmission mechanism, and the second simulation piece fixture is installed with a second blade root platform simulation piece; a laser vibrometer. The invention combines experimental research and contact parameter estimation to perform specific quantitative evaluation on the motion characteristics of the friction damper, and can systematically study the dynamic characteristics of the dry friction damping of the blade material of the gas turbine.

Description

technical field [0001] The invention belongs to the technical field of metal material dry friction damping mechanism testing, in particular to an experimental testing system and method for dry friction damping dynamic characteristics. Background technique [0002] For gas turbine compressors and turbine blades with dry friction damping structure, the friction between the contact surfaces is the key to dissipate the vibration energy of the blades. In-depth research on the dynamic characteristics of friction damping between the contact surfaces is important for revealing the dryness of the turbine blades. Friction damping vibration characteristics are very important. Due to the highly complex nonlinear characteristics of dry friction, the friction models proposed by theoretical analysis are simplified to a certain extent, and it is difficult to solve them accurately. Therefore, the experimental test is still to determine the dynamic characteristics of the blade root platform-f...

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Problems solved by technology

[0003] At present, some scholars have used experimental methods to conduct preliminary research on the dynamic characteristics of frictional damping between the contact surfaces of metal materials. There are few studies on alloy steel materials

The high-temperature nickel-based alloy steel material has high specific strength, high elastic modulus, and small thermal expansion coefficient. Under the same excitation conditions, it is less likely to deform than ordinary carbon steel. The obtained friction hysteresis curve is quite different from the properties of high-temperature nickel-based alloys and cannot be directly applied. Therefore, it is necessary to design an experimental test system that can accurately generate and measure the dynamic characteristics of dry friction damping for gas turbine high-temperature nickel-based alloy materials.

On the other hand, most of the current experiments study the overall influence of the friction damper on the blade from the two aspects of vibration reduction amplitude and resonance frequency shift. This black box-like method is used to evaluate the ability of the friction damper to reduce the resonance displacement. The contact characteristic parameters are obtained on the basis of direct experimental research, so it is impossible to conduct a specific quantitative evaluation of the kinematic characteristics of the friction damper; and each experiment is only measured and studied for its own working conditions, and it is difficult to form a friction contact characteristic parameter database suitable for engineering technology , and these parameters have an important influence on the dry friction damping vibration characteristics of gas turbine blades, and further research is needed

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