| The most of failure phenomena of modern equipments are caused by fatigue and friction and they interact with each other in a complex way,so whether purely from the viewpoint of tribology or purely form the viewpoint of mechanical fatigue,to evaluate the damage,life span or limit of a special mechanical system completely is impossible.Therefore it has important practical significance to study the composite damage mechanism of friction and fatigue.The possible factors influencing the compound action of sliding friction and fatigue are determined.The mechanism and the interaction of these factors are analyzed.Interaction factors are determined after disposing and analyzing the dates.A typical sliding friction and fatigue model is built by ANSYS finite element analysis software,taking J-integral as reference,the influence of sliding contact effect on crack tip stress filed was investigated by fracture mechanics and finite element analyses under dry friction.The variation regulation of crack tip stress field under different friction coefficient,different contact pressure,different crack length and different crack morality were obtained.The variation of crack tip stress field is different with crack morality while the friction effect is considered,the increasing of friction effect aggravate variation of the crack tip stress field for vertical crack.For oblique crack,the increasing of friction effect weakens variation of the crack tip stress field in the vicinity of sliding to crack.The fluctuation range of crack tip stress increase with contact pressure increasing.The included angle between the direction of the sliding velocity and the crack is smaller,the crack tip stress field changed more significantly.The stress field intensity gradually augments,and then gradually monishes with crack length increasing.The fatigue life is analyzed by FE-SAFE fatigue analysis software.The variation of the fatigue life under the load,the friction coefficient and the different forms of the crack is analyzed in detail.In general,the fatigue life is closely related to the change of the crack tip stress field under the specific load.The more volatile the crack tip stress field fluctuates,the lower the fatigue life. |
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