scholarly journals Dynamic Analysis of a Bladed Disk With Friction and Fretting-Wear in Blade Attachments

2009 ◽  
Author(s):  
Loi¨c Salles ◽  
Laurent Blanc ◽  
Fabrice Thouverez ◽  
Aleksander M. Gouskov ◽  
Pierrick Jean
Keyword(s):  
Jacobian Matrix ◽  
Relative Displacement ◽  
Correction Method ◽  
Fretting Wear ◽  
Wear Depth ◽  
Industrial Plants ◽  
Friction Dampers ◽  
Coulomb’S Friction ◽  
Bladed Disk ◽  
Wear Damage

Assembled bladed disks have many contact interfaces (blade-disk joint, blade shrouds, friction dampers...). Because of relative displacements at these interfaces, fretting-wear occurs, which affects negatively the lifetime of the structure. Methods exist to predict fretting-wear in quasi-static analysis. However they don’t predict all the phenomena observed in blade attachments on real industrial plants. This paper studies the assumption of a responsibility of dynamics for fretting-wear damage. A numerical treatment of fretting-wear under vibratory loading is proposed. The method is based on the Dynamical Lagrangian Frequency Time method. It models unilateral contact through Coulomb’s friction law. The basic idea is to separate time in two scales, slow scale for tribological phenomena and fast scale for dynamics. For a chosen number of periods of vibration, a steady state is assumed and the variables are decomposed in Fourier series. An Alternating Frequency Time procedure is performed to calculate the non-linear forces. Then, a Hybrid Powell’s algorithm is used as solver. A quasi-analytical expression of the Jacobian matrix decreases the duration of calculations. This expression is also used to predict new relative displacement at the interfaces due to the increase of wear depth. This method is similar to a prediction-correction method, with wear depth as the term of continuation. Numerical investigations on a bladed-disk with friction contact interfaces illustrate the performances of this method and show the coupling between dynamical and tribological phenomena.

scholarly journals Literature Review on Fretting Wear and Contact Mechanics of Tribological Coatings

Coatings ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 501 ◽  
Author(s):  
Lifeng Ma ◽  
Kilho Eom ◽  
Jean Geringer ◽  
Tea-Sung Jun ◽  
Kyungmok Kim
Keyword(s):  
Literature Review ◽  
Contact Mechanics ◽  
Relative Displacement ◽  
Fretting Wear ◽  
Tribological Coatings ◽  
Review Study ◽  
Stress States ◽  
Wear Damage ◽  
Industrial Solutions ◽  
Fretting Damage

This article reviews fretting wear damage in industries and in the contact mechanics of coated systems. Micro-slip motion resulting in fretting damage is discussed along with major experimental factors. The experimental factors, including normal force, relative displacement, frequency and medium influence are directly compared. Industrial solutions to reduce fretting damages are then discussed. The contact mechanics of a coated system are reviewed to quantify stress states in a coating layer and the substrate. Finally, a literature review on simulation for fretting is carried out. This review study provides useful methods and practical solutions to minimize fretting wear damage.

Fretting Wear Damage of the Corroded Fuel Cladding Tubes for Nuclear Fuel Rod against Supporting Grids

2007 ◽  
Vol 345-346 ◽  
pp. 709-712
Author(s):  
Jin Seon Kim ◽  
Yong Hwan Kim ◽  
Seung Jae Lee ◽  
Young Ze Lee
Keyword(s):  
Nuclear Fuel ◽  
Nuclear Power ◽  
Fluid Flows ◽  
Fretting Wear ◽  
Wear Depth ◽  
Fuel Cladding ◽  
Flow Induced Vibration ◽  
Nuclear Fuel Assembly ◽  
Wear Damage ◽  
Increasing Load

Fuel cladding tubes in nuclear fuel assembly are held up by supporting grids because the tubes are long and slender. Fluid flows of high-pressure and high-temperature in the tubes cause oscillating motions between tubes and supports. This is called as FIV (flow induced vibration), which causes fretting wear in contact parts of tube-support. The fretting wear of tube-support can threaten the safety of nuclear power plant. Therefore, a research about the fretting wear characteristics of tube-support is required. The fretting wear tests were performed with supporting grids and cladding tubes, especially after corrosion treatment on tubes, in water. The tests were done using various applied loads with fixed amplitude. From the results of fretting tests, the wear amounts of tube materials can be predictable by obtaining the wear coefficient using the work rate model. Due to stick phenomena the wear depth was changed as increasing load and temperature. The maximum wear depth was decreased as increasing the water temperatures. At high temperatures there are the regions of some severe adhesion due to stick phenomena.

Steam Generator Fretting-Wear Damage: A Summary of Recent Findings

1999 ◽  
Vol 121 (3) ◽  
pp. 304-310 ◽  
Author(s):  
F. M. Gue´rout ◽  
N. J. Fisher
Keyword(s):  
Steam Generator ◽  
Wear Test ◽  
Operating Conditions ◽  
Fretting Wear ◽  
Measuring System ◽  
Effect Of Temperature ◽  
Design Parameters ◽  
Wear Depth ◽  
Alloy 800 ◽  
Wear Damage

Flow-induced vibration of steam generator (SG) tubes may sometimes result in fretting-wear damage at the tube-to-support locations. Fretting-wear damage predictions are largely based on experimental data obtained at representative test conditions. Fretting-wear of SG materials has been studied at the Chalk River Laboratories for two decades. Tests are conducted in fretting-wear test machines that simulate SG environmental conditions and tube-to-support dynamic interactions. A new high-temperature force and displacement measuring system was developed to monitor tube-to-support interaction (i.e., work-rate) at operating conditions. This improvement in experimental fretting-wear technology was used to perform a comprehensive study of the effect of various environment and design parameters on SG tube wear damage. This paper summarizes the results of tests performed over the past 4 yr to study the effect of temperature, water chemistry, support geometry and tube material on fretting-wear. The results show a significant effect of temperature on tube wear damage. Therefore fretting-wear. The results show a significant effect of temperature or tube wear damage. Therefore, fretting-wear tests must be performed at operating temperatures in order to be relevant. No significant effect of the type of water treatment on tube wear damage was observed. For predominantly impacting motion, the wear of SG tubes in contact with 410 stainless steel is similar regardless of whether Alloy 690 or Alloy 800 is used as tubing material or whether lattice bars or broached hole supports are used. Based on results presented in this paper, an average wear coefficient value is recommended that is used for the prediction of SG tube wear depth versus time.

Optimization of Interblade Friction Damper Design

2000 ◽  
Author(s):  
Lars Panning ◽  
Walter Sextro ◽  
Karl Popp
Keyword(s):  
Equations Of Motion ◽  
Turbine Blades ◽  
Relative Displacement ◽  
Contact Forces ◽  
Hertzian Contact ◽  
Computation Method ◽  
Friction Damper ◽  
Friction Dampers ◽  
Advantages And Disadvantages ◽  
Bladed Disk

The vibration amplitudes of bladed disk assemblies can be reduced significantly by means of friction damping devices such as shrouds, damping wires and interblade friction dampers. In practice, interblade friction dampers are applied in rotating arrangements with various geometries showing curved or flat surfaces like so-called wedge-shaped dampers. This paper is focusing on a computation method to predict the dynamical behaviour of turbine blades with friction dampers including both, curved and wedge-shaped dampers with Hertzian and non-Hertzian contact conditions, respectively. The presented computation method uses a 3D contact model to calculate the contact forces, including normal and tangential stiffnesses, roughness and microslip effects. The relative displacements in the contact area can be expressed by means of 6 DOF of the blade platforms and 6 rigid body DOF of the damper including translational and rotational displacements. The relative displacement of the friction damper with respect to the adjacent blades can be derived from the contact kinematics of the blade-damper-blade system and the equations of motion of the friction damper. Thus, the model can be applied to investigate spatial motions of the bladed disk assembly including bending and torsional vibrations. A comparison of different friction damper designs with respect to an optimal damper geometry and damper mass is presented. The advantages and disadvantages of each design will be discussed. Experimental results are shown to validate the developed computation method.

scholarly journals Improved Reliability of Bladed Disks due to Friction Dampers

1997 ◽  
Author(s):  
Walter Sextro ◽  
Karl Popp ◽  
Ivo Wolter
Keyword(s):  
Dry Friction ◽  
Three Dimensional ◽  
Line Contact ◽  
Two Dimensional ◽  
Centrifugal Forces ◽  
Friction Damper ◽  
Blade Vibration ◽  
Friction Dampers ◽  
Bladed Disk ◽  
Bladed Disk Assembly

Friction dampers are installed underneath the blade platforms to improve the reliability. Because of centrifugal forces the dampers are pressed onto the platforms. Due to dry friction and the relative motion between blades and dampers, energy is dissipated, which results in a reduction of blade vibration amplitudes. The geometry of the contact is in many cases like a Hertzian line contact. A three-dimensional motion of the blades results in a two-dimensional motion of one contact line of the friction dampers in the contact plane. An experiment with one friction damper between two blades is used to verify the two-dimensional contact model including microslip. By optimizing the friction dampers masses, the best damping effects are obtained. Finally, different methods are shown to calculate the envelope of a three-dimensional response of a detuned bladed disk assembly (V84.3-4th-stage turbine blade) with friction dampers.

Assessment of Fretting‐Wear Damage in Nuclear and Process Equipment

2021 ◽  
pp. 373-395
Author(s):  
Michel J. Pettigrew ◽  
Metin Yetisir ◽  
Nigel J. Fisher ◽  
Bruce A. W. Smith ◽  
Victor P. Janzen
Keyword(s):  
Fretting Wear ◽  
Process Equipment ◽  
Wear Damage

Fretting Wear Mechanisms and Their Effects on Fretting Fatigue

1988 ◽  
Vol 110 (3) ◽  
pp. 517-524 ◽  
Author(s):  
Y. Berthier ◽  
Ch. Colombie´ ◽  
L. Vincent ◽  
M. Godet
Keyword(s):  
Fretting Fatigue ◽  
Relative Displacement ◽  
Contact Condition ◽  
Fretting Wear ◽  
Initial Contact ◽  
Great Care ◽  
Third Body ◽  
Body Formation ◽  
The Third ◽  
Contact Surfaces

Fretting wear and fretting fatigue are governed by the rate of formation of materials (third-bodies) between the initial contact surfaces. Furthermore, the third-bodies must be maintained within the contact. The issue of the race between third-body formation and subsurface damage conditions the effect of fretting on fatigue. That race lasts for only a few hundred or at best a few thousand cycles. Effective third-bodies (or good anti-fretting lubricants) must adhere strongly to the rubbing surfaces, and be able to accommodate at least part of the relative displacement. Great care in the design of test equipment has to be exercised before definitive results on the effect of amplitude and frequency on either fretting fatigue or fretting wear can be obtained for a given contact condition, given materials and given environments.

Effects of Intentional Large Mistuning to the Performance of B–B Friction Dampers in the Mistuned Bladed Disk Assembly Subjected to Narrow band Random Excitation

2021 ◽  
Author(s):  
Douksoon Cha
Keyword(s):  
Simple Model ◽  
Efficient Method ◽  
Narrow Band ◽  
Random Excitation ◽  
Additional Mass ◽  
Friction Dampers ◽  
Analytical Technique ◽  
Bladed Disk ◽  
Bladed Disk Assembly

Abstract In this study, the effects of intentional mistuning on the performance of B–B friction dampers are investigated in an inherently mistuned bladed disk assembly subjected to narrow band random excitation. The intentional large mistuning and inherent small mistuning are modeled by the additional mass and perturbations in the stiffness of the blade, respectively. It was found that the performance of B–B friction dampers improved owing to the intentional mistuning of the correlated excitations. Based on a simple model of an intentionally and inherently mistuned bladed disk assembly, the analytical technique offers an efficient method to evaluate the effects of intentional mistuning and friction dampers.

A Numerical Simulation of Fretting Wear considering the Dynamic Evolution of Debris for the Coated Contact Surface

2021 ◽  
pp. 1-49
Author(s):  
Li Xiao ◽  
Yingqiang Xu ◽  
Zhiyong Chen
Keyword(s):  
Fretting Wear ◽  
Contact Pair ◽  
Dynamic Evolution ◽  
Wear Depth ◽  
Wear Coefficient ◽  
Wear Model ◽  
Wear Process ◽  
Dlc Coating ◽  
Wear Life ◽  
Wear Calculation

Abstract In this paper, a multi-layer body model in which material properties and wear coefficient change with node coordinates is proposed, so that the wear profile is not restricted by the singularity of the interface of the coated contact pairs. The conversion rate of the adhered particles was obtained to describe the growth and expansion of the debris at the fretting interface based on experiments, and the wear model of coated contact pair considering the dynamic evolution of the debris layer was established. By comparing the previous experimental and computational results, the wear calculation method proposed in this paper is more reasonable to predict the wear profile of the coated contact pair. In addition, the influence of the debris layer on the wear depth, friction width, and contact pressure in the fretting process is analyzed, indicating that the existence of the debris layer can delay the wear process. Finally, the fretting wear life of the SCMV steel contact pair deposited with the W-DLC coating is estimated.

Fretting wear damage of HexTOOL™composite depending on the different fibre orientations

2009 ◽  
Vol 5 ◽  
pp. 012019
Author(s):  
S Terekhina ◽  
M Salvia ◽  
S Fouvry ◽  
G Malysheva ◽  
T Tarasova
Keyword(s):  
Fretting Wear ◽  
Wear Damage
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