Investigation On Vibration Characteristics For Blade With A Wedge Damper

Aero-engine blades are susceptible to fatigue failure or fault fracture under large vibration stress,and the vibration can be suppressed by a dry friction damping structure.Platform damping structure by sliding friction between the contact surface consumption of vibration energy,simple and significant effect,it has a wide range of applications.It is of great theoretical significance and practical application value to study the vibration attenuation mechanism of the dry friction damping and the influence of the damper on the vibration response of the blade.Based on the wedge damper structure,an macro-micro sliding model has been deduced,and a vibration response analysis method has been established for the blade with a wedge damper.The influence of different parameters on the damping effect of the dampers and the influence of the angle difference of the different excitation directions on the vibration response of the blade have been analyzed by examples and experiments.Finally,the influence of different contact variables between the contact surface of the wedge damper and radian damper and the platform on the contact state has been studied.The main work of this paper is as follows:(1)The normal load of the friction surface is assumed to be a linear distribution,and the wholelocal unified sliding friction interface model has been deduced.The equivalent stiffness and damping of the wedge damper have been deduced by the energy method and the second-order harmonic balance method,which are combined with the solution of the non-linear equation of the damping structure dynamics model.(2)Based on the macro-micro slip model of wedge damper,the vibration response analysis and calculation program of the system with dry friction damping device has been developed by combining VS2010 with APDL in ANSYS.The influence of structural parameters and shape of different wedge dampers on the damping effect has been analyzed.The influence of the difference of different angles of excitation on the vibration characteristics of the blade has also been studied under the double excitation system.(3)Designed and built a single-excitation and a double-excitation vibration system test-bed.The experiment of damping characteristics of blade with wedge damper has been carried out,and its results are in good agreement with the calculated results.So the validity of the whole-local uniform sliding model of the wedge damper and the vibration response analysis method of the blade with the dry friction dampers are verified.(4)The influence of the friction coefficient between the damper and the edge plate,the structural parameters of dampers and the different rotating speed of the disc on the contact surface characteristics have been studied by contact analysis of the disc structure with the wedge damper and with the radian damper.The analysis results show that the contact probability of radian damper is larger,which is more favorable for vibration reduction.