Dynamic Simulation Of Fretting Wear Of Bolted Joint

Fretting wear is a kind of material damage in contact surfaces caused by micro relative displacement between two bodies.It can change the profile of contact surfaces,resulting in loose of bolted joint or fatigue cracks.Fretting wear exists in various fields.Fretting wear is easily overlooked because it has the characteristics of small displacement amplitude,small amount of wear,and concealed position.However,the failure and damage of key components are often related to it.Finite element method(FEM)is an effective method to simulate the evolution of fretting wear process.The bolted joint is equivalent to a two-dimensional cylinder/flat model,and the finite element model is established in ABAQUS.The critical function of the two sliding conditions was obtained by studying the contact stress and the relative slip distance of the contact area under different loading conditions.This paper combines the energy cons?mption model and the FORTRAN language to write the UEMSHMOTION subroutine applicable to this model.It realizes the dynamic updating of wear surface nodes and establishes the finite element wear model.On this basis,this paper studies the variation law of the friction coefficient between contact surfaces of cylinder/plane contact type.Combining the change function of the friction coefficient with the n?mber of accelerations,a step function with the n?mber of times of acceleration is obtained.The friction coefficient corresponds to the analysis step of different cycles.Combined with the energy cons?mption model and the ?MSHMMOTION user subroutine,a wear model considering the variable friction coefficient was established.The fretting wear simulation considering variable friction coefficient was realized in finite element software.Through the simulation analysis of wear depth and wear vol?me under different conditions,this paper studies the influence of cycle times,normal load and displacement amplitude on fretting wear.The simulation results of two kinds of wear models reveal the influence of constant friction coefficient and variable friction coefficient on fretting wear.