Dynamic analysis of fretting-wear in friction contact interfaces

Accurate prediction of the vibration response of aircraft engine assemblies is of great importance when estimating both the performance and the lifetime of their individual components. In the case of underplatform dampers, for example, the motion at the frictional interfaces can lead to a highly nonlinear dynamic response and cause fretting wear at the contact. The latter will change the contact conditions of the interface and consequently impact the nonlinear dynamic response of the entire assembly. Accurate prediction of the nonlinear dynamic response over the lifetime of the assembly must include the impact of fretting wear. A multi-scale approach that incorporates wear into the nonlinear dynamic analysis is proposed, and its viability is demonstrated for an underplatform damper system. The nonlinear dynamic response is calculated with a multiharmonic balance approach, and a newly developed semi-analytical contact solver is used to obtain the contact conditions at the blade-damper interface with high accuracy and low computational cost. The calculated contact conditions are used in combination with the energy wear approach to compute the fretting wear at the contact interface. The nonlinear dynamic model of the blade-damper system is then updated with the worn profile and its dynamic response is recomputed. A significant impact of fretting wear on the nonlinear dynamic behaviour of the blade-damper system was observed, highlighting the sensitivity of the nonlinear dynamic response to changes at the contact interface. The computational speed and robustness of the adopted multi-scale approach are demonstrated.

show abstract

“…A study of fretting-wear in dovetail attachments during blade-disk vibration was described in a previous paper [5,6] and it was shown that steady state can occur. Therefore it would be useful to have a method capable of calculating the steady state caused by fretting-wear under dynamical loading directly.…”

Section: Fretting-wear With Pseudo-timementioning

confidence: 99%

“…For CFD applications, several authors [1,3,4] propose transforming the non-linear algebraic system into a first order differential system and integrating it to obtain the steady state and thus the solution of the non-linear system. The second section sets out the theory of this method and different schemes are tested by using numerical examples.In previous papers [5][6][7] we have shown that steady state in fretting-wear can occur during vibration. To identify steady state we proposed an integration scheme involving the calculation of transient kinetics.…”

mentioning

confidence: 93%

Dual Time Stepping Algorithms With the High Order Harmonic Balance Method for Contact Interfaces With Fretting-Wear

Salles

¹

,

Blanc

²

,

Thouverez

³

et al. 2011

Volume 6: Structures and Dynamics, Parts a and B

View full text Add to dashboard Cite

Contact interfaces with dry friction are frequently used in turbomachinery. Dry friction damping produced by the sliding surfaces of these interfaces reduces the amplitude of bladed-disk vibration. The relative displacements at these interfaces lead to fretting-wear which reduces the INTRODUCTIONSources of non-linearity in turbomachinery are multiple. Contact with friction is one of the most important causes of non-linearity in turbomachinery, especially in bladed-disks. Contact with friction must be taken into account to ensure efficient that the vibration of this type of structure can be predicted well. Friction dampers can be added to decrease response to vibration, although this requires numerical tools to evaluate the added damping rate. In bladed disks, contact with friction occurs at the interfaces between the blades and the disk to which they are attached. Fluid is another source of non-linearity. It is possible to simulate the periodic behaviour of coupled fluid-structures by using the frequency method.HBM (Harmonic Balance Method) is the most widely used frequency method. It is based on the expansion of variables in Fourier series and the Galerkin procedure to obtain non-linear algebraic systems. For systems with contact and friction, an alternating frequency time (AFT) procedure is performed to calculate non-linear forces in the time domain and then transform them into the frequency domain.Other approaches are possible, in this paper we study two other methods: the trigonometric collocation method (TCM) and the high dimension harmonic balance method (HDHB). In TCM a non-linear algebraic system is solved in the time domain. In the HDHB method the unknowns are values of displacements with an equal time step and the non-linear algebraic system is solved once again in the time domain. Some authors have called this method the time spectral method (TSM) [1] and it was used in CFD and proved highly efficient.In the first section we present the theory underlying these methods and explain the advantages of each one. Different strategies are possible for solving non-linear algebraic systems the most common of which is Newton-Raphson solver [2]. For very large systems a Jacobian matrix can be ill-conditioned, with problems of convergence in the linear direction search step. For CFD applications, several authors [1,3,4] propose transforming the non-linear algebraic system into a first order differential system and integrating it to obtain the steady state and thus the solution of the non-linear system. The second section sets out the theory of this method and different schemes are tested by using numerical examples.In previous papers [5][6][7] we have shown that steady state in fretting-wear can occur during vibration. To identify steady state we proposed an integration scheme involving the calculation of transient kinetics. A method that allows finding the steady state directly would be very useful. In this paper we propose using a pseudo-time method and integrating wear kinetics in pseudo-time. It is s...

show abstract

“…This allows a much finer discretisation of the contact area while keeping computational cost low. Salles et al [8,9] also used a multi-scale approach but they proposed a numerical treatment of fretting-wear under vibratory loading. In their approach, two separate time scales are used: a slow scale for tribological phenomena and a fast scale for dynamics.…”

Section: Introductionmentioning

confidence: 99%

A Multiscale Approach for Nonlinear Dynamic Response Predictions With Fretting Wear

Armand

¹

,

Pesaresi

²

,

Salles

³

et al. 2016

Journal of Engineering for Gas Turbines and Power

Self Cite

View full text Add to dashboard Cite

Accurate prediction of the vibration response of aircraft engine assemblies is of great importance when estimating both the performance and the lifetime of their individual components. In the case of underplatform dampers, for example, the motion at the frictional interfaces can lead to a highly nonlinear dynamic response and cause fretting wear at the contact. The latter will change the contact conditions of the interface and consequently impact the nonlinear dynamic response of the entire assembly. Accurate prediction of the nonlinear dynamic response over the lifetime of the assembly must include the impact of fretting wear. A multi-scale approach that incorporates wear into the nonlinear dynamic analysis is proposed, and its viability is demonstrated for an underplatform damper system. The nonlinear dynamic response is calculated with a multiharmonic balance approach, and a newly developed semi-analytical contact solver is used to obtain the contact conditions at the blade-damper interface with high accuracy and low computational cost. The calculated contact conditions are used in combination with the energy wear approach to compute the fretting wear at the contact interface. The nonlinear dynamic model of the blade-damper system is then updated with the worn profile and its dynamic response is recomputed. A significant impact of fretting wear on the nonlinear dynamic behaviour of the blade-damper system was observed, highlighting the sensitivity of the nonlinear dynamic response to changes at the contact interface. The computational speed and robustness of the adopted multi-scale approach are demonstrated.

show abstract

Dynamic analysis of fretting-wear in friction contact interfaces

Cited by 34 publications

References 29 publications

A Multi-Scale Approach for Nonlinear Dynamic Response Predictions With Fretting Wear

A Multi-Scale Approach for Nonlinear Dynamic Response Predictions With Fretting Wear

Dual Time Stepping Algorithms With the High Order Harmonic Balance Method for Contact Interfaces With Fretting-Wear

A Multiscale Approach for Nonlinear Dynamic Response Predictions With Fretting Wear

Contact Info

Product

Resources

About