Modelování dráhy trhliny v železničním kole v podmínkách kontaktní únavy

Crack path modelling in railway wheel under rolling contact fatigue

journal article - other

en

A computational model of crack path for two-dimensional primary crack situated in a railway wheel rim is designed. The railway wheel rim is placed on thewheel disc of railway wheel with interference fit. Crack behaviour is analysed in the case of rectilinear ride of a train under rolling contact fatigue. Plank and Kuhn criterion is used to decide whether crack will either kink and follow mode I controlled (tensile mode) path, or it will propagate coplanar mode II controlled (shear mode). If mode I controlled crack growth is more probable then a direction of crack propagation is predicted using the maximum tensile stress range criterion. In this way a relationship between stress intensity factors and crack geometry is obtained. For comparison, crack behaviour in a solid railway wheel which is not subjected to pre-stress loading is also analysed. In the latter case the contact forces in the wheel-rail contact are considered to have i) only normal part ii) both the normal part and tangential part.

Byl navržen výpočetní model dráhy trhliny pro dvojrozměrnou primární trhlinu v ráfku železniční kola. Ráfek železničního kolo je nasazen na disk železničního kola s přesahem. Je analyzováno chování trhliny při kontaktní únavě v případě přímočaré jízdu vlaku. Plankovo-Kuhnovo kritérium je použito pro rozhodování, zdali se trhlina bude šířit koplanárně v módu II nebo dojde k ohybu trhliny a jejímu růstu v módu I. V druhém případě je pro směr růstu trhliny použito kriterium maximálního tahového napětí.

A computational model of crack path for two-dimensional primary crack situated in a railway wheel rim is designed. The railway wheel rim is placed on thewheel disc of railway wheel with interference fit. Crack behaviour is analysed in the case of rectilinear ride of a train under rolling contact fatigue. Plank and Kuhn criterion is used to decide whether crack will either kink and follow mode I controlled (tensile mode) path, or it will propagate coplanar mode II controlled (shear mode). If mode I controlled crack growth is more probable then a direction of crack propagation is predicted using the maximum tensile stress range criterion. In this way a relationship between stress intensity factors and crack geometry is obtained. For comparison, crack behaviour in a solid railway wheel which is not subjected to pre-stress loading is also analysed. In the latter case the contact forces in the wheel-rail contact are considered to have i) only normal part ii) both the normal part and tangential part.

únavová trhlina v podmínkách valivého kontaktu, neproporcionální zatížení, smíšený mód, železniční kolo, FEM

rolling contact fatigue crack, non-proportional loading, mixed mode, railway wheel, FEM

2015

31.12.2015

University of West Bohemia

Česká republika, Plzeň

1802-680X

9

2

103–126

24