The impact of fretting wear on structural dynamics: Experiment and Simulation

A Fantetti,M Volvert,L Liu,L Salles,I Lawal,C.W Schwingshackl,L.R Tamatam,D Nowell,M.R.W Brake

doi:10.1016/j.triboint.2019.05.023

Abstract

Abstract This paper investigates the effects of fretting wear on frictional contacts. A high frequency friction rig is used to measure the evolution of hysteresis loops, friction coefficient and tangential contact stiffness over time. This evolution of the contact parameters is linked to significant changes in natural frequencies and damping of the rig. Hysteresis loops are replicated by using a Bouc-Wen modified formulation, which includes wear to simulate the evolution of contact parameters and to model the evolving dynamic behaviour of the rig. A comparison of the measured and predicted dynamic behaviour demonstrates the feasibility of the proposed approach and highlights the need to consider wear to accurately capture the dynamic response of a system with frictional joints over its lifetime.

Highlights

A major challenge in the modelling of the dynamics of jointed structures is the accurate characterization of the contact forces occurring at friction interfaces
These contact models have been successfully used in combination with harmonic balance solvers [12,13,14,15,16] or time integration techniques [17, 18] to model the dynamics of realistic structures such as flanges [19], blades equipped with dampers or shrouds [20,21,22,23,24] or lap joints [17]
Experimental Results Three pieces of information were obtained during each test: the evolution of hysteresis loops, contact interfaces, and system dynamics

Summary

Introduction

A major challenge in the modelling of the dynamics of jointed structures is the accurate characterization of the contact forces occurring at friction interfaces. Several contact models have been proposed over the years to describe the contact behaviour under oscillatory loadings [1,2,3,4,5,6,7,8,9,10,11], with the most common model being a Coulomb slider in series with a spring (Jenkins element [5, 6]) These contact models have been successfully used in combination with harmonic balance solvers [12,13,14,15,16] or time integration techniques [17, 18] to model the dynamics of realistic structures such as flanges [19], blades equipped with dampers or shrouds [20,21,22,23,24] or lap joints [17].

Objectives

Results

Conclusion