Experimental Study of Dynamic Characteristics of Dry Friction Damping of Turbine Blade Steel

For lot of structures, especially turbine blades, damper can dissipate the vibration energy by friction. Investigating the property of metal dry friction damping can give many usable data for response analysis of damping blade which is important in damped blade designs. The paper constructs an experimental rig and carries out experiment with pieces having radius of curvature 6mm, 12mm and 24mm. The relative displacement between contact surfaces and the friction force changed with time were obtained for different initial pressure and frequency of exciting force. Hysteresis curves of dry friction damper were derived. The variations of friction coefficient of stick-slip area, equivalent stiffness and equivalent damping were calculated based on experimental data.

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Stability Analysis of a Vibrational System Subject to Negative Viscous Damping and Displacement-Dependent Dry Friction Damping

Volume 5: 19th Biennial Conference on Mechanical Vibration and Noise, Parts A, B, and C ◽

10.1115/detc2003/vib-48488 ◽

2003 ◽

Author(s):

Aldo A. Ferri ◽

Wayne E. Whiteman

Keyword(s):

Stability Analysis ◽

Friction Force ◽

Dry Friction ◽

Effective Means ◽

Viscous Damping ◽

Friction Damper ◽

Friction Damping ◽

Fan Blade ◽

The Stability ◽

Dry Friction Damping

A stability analysis is conducted of an autonomous single-degree-of-freedom system damped with negative viscous damping and a displacement-dependent Coulomb friction force. The geometry of the dry friction damping element yields a friction force that grows linearly with the system displacement. The most direct application of this system is in the study of a turbomachinery blade with shroud interfaces designed to achieve this geometry. Recent studies have shown that the damping of systems with this type of displacement-dependent dry friction force resembles linear structural damping and suggests that this arrangement may be an effective means of flutter suppression in these turbine and fan blade applications. For this study, the inclusion of negative viscous damping is used in order to approximate destabilizing aerodynamic forces. An exact analysis is conducted to determine the stability of this autonomous system. Results show that energy losses from the displacement-dependent dry friction damper are large enough to achieve local and even global stability under certain conditions.

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Effect of Intentional Dry Friction Damping on the Performance of an Elastomeric Engine Mount

ASME 2010 10th Biennial Conference on Engineering Systems Design and Analysis, Volume 3 ◽

10.1115/esda2010-24276 ◽

2010 ◽

Cited By ~ 2

Author(s):

Caner Boral ◽

Ender Cig˘erog˘lu ◽

I˙brahim Korkmaz

Keyword(s):

Dry Friction ◽

Vibration Isolation ◽

Wide Frequency Range ◽

Friction Damper ◽

Friction Damping ◽

Automotive Engine ◽

Engine Mounts ◽

Initial Cost ◽

Engine Mount ◽

Dry Friction Damping

Automotive engine mounts are used to protect engine from road irregularities and to isolate transmission of vibrations created by the engine which have a drastic effect on the noise generated inside the passenger cabin. Most common types of engine mounts are elastomeric and hydraulic mounts, the former having better vibration isolation characteristics whereas the latter displays better shock isolation. Elastomeric mounts are widely used for their low initial cost, while hydraulic mounts with inertia track and decoupler are chosen for their good vibration isolation and shock excitation characteristics. However, hydraulic mounts with inertia track and decoupler are not appropriate for small segment and commercial vehicles due to their high initial cost. In this paper, the effect of the addition of a dry friction damper on the performance of elastomeric automobile engine mounts is investigated. Results showed that addition of dry friction damping to the elastomeric engine mount significantly improves the transmissibility throughout a wide frequency range where the best results are obtained at the resonance frequency.

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