Fretting fatigue life prediction model and method considering surface roughness

Abstract

The invention discloses a fretting fatigue life prediction model and method considering surface roughness, and the method is based on continuous medium damage mechanics, and the surface roughness of a material surface impacted by different laser energy is different. The residual compressive stress is introduced into the finite element model, and the fretting fatigue life can be predicted more accurately by considering the change of the surface roughness. The method comprises the following steps: (1) establishing a finite element model, and adding residual compressive stress introduced by laser shock peening into the model as initial stress; (2) carrying out simulation calculation and extracting related parameters in the model; (3) fitting parameters in the life prediction model, and establishing a full fretting fatigue life prediction formula; and (4) establishing new finite element analysis, and calculating the fretting fatigue life by using a life prediction formula. The model and the method can effectively predict fretting fatigue life of different surface roughness, and have important engineering application value.

Description

technical field [0001] The invention belongs to the field of prediction and simulation of fretting fatigue life, in particular to a method for establishing and applying a fretting fatigue life prediction model considering the surface roughness of materials. Background technique [0002] Fretting is a reciprocating motion with extremely small amplitude (on the order of microns) that occurs between two contact surfaces. This motion is usually caused by external vibration or deformation. When one of the objects in contact with each other is subjected to alternating stress, the fretting phenomenon It will cause the early initiation and growth of fatigue cracks, that is, the problem of fretting fatigue. Different from the failure form of ordinary fatigue, the fretting contact area is affected by many complex factors, and the crack initiation position of fretting fatigue is usually not located at the maximum stress point or strain point of the component, which brings great difficu...

AI Technical Summary

Problems solved by technology

In the currently formed fretting fatigue life prediction model method, researchers have taken into account the differences in friction coefficients of different materials and considered them in the finite element modeling process, but they have not considered other effects of surface roughness.

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