A NEW NON-LINEAR CONTINUUM DAMAGE MECHANICS MODEL FOR THE FATIGUE LIFE PREDICTION UNDER VARIABLE LOADING
Keywords: non-linear fatigue damage accumulation, continuum damage mechanics, mean stress, loading sequence, fatigue life prediction
AbstractFatigue is a damage accumulation process in which material property deteriorates continuously. For the usual failure mode of mechanical components under vari-able loading, fatigue life prediction issues are very impor-tant for selection, design, and safety assessments of these components. Based on continuum damage mechanics theory, this paper presents a new non-linear fatigue dam-age accumulation model for fatigue life prediction under variable loading. The proposed model has been formulated to take the damage evolution of material and the effects of loading sequence on fatigue life under dif-ferent loading conditions into account. Moreover, it con-siders the mean stress effects through characterizing the damage evolution of materials with fewer parameters. Experimental data of 30NiCrMoV12 and 30CrMnSiA under two-stress level loading from literature were used to verify the proposed model. Predicted fatigue lives using the proposed model show a good agreement with the reported experimental data.
MECHANICS OF SOLID BODIES