Numerical analysis of rolling contact fatigue crack initiation Considering material microstructure

The material microstructure of plays an important role in crack initiation of rolling contact fatigue. To address crack initiation of tapered roller bearings, the inhomogeneous characteristic of material is considered. The random distribution of material grains is simulated with Voronoi graph, and a Voronoi finite element model of rolling contact fatigue is given. Numerical analysis of damage-life constitutive relation is carried out with finite element analysis. The effect of material microstructure inhomogeneity on initiation life of fatigue crack is studied. Researches show that the smaller the grain size, the more difficult the fatigue crack appearing. The larger the difference of elasticity modulus between non-metallic inclusions and matrix material, the greater the impact on fatigue life of crack initiation. The angular and sharp non-metallic inclusions reduce fatigue life more than rounded shape inclusions. Initiation life of fatigue crack has a minimum value on a critical depth of nonmetallic inclusion. The longer distance between two laterally arranged inclusions, the greater it affect the initiation life of fatigue crack. The effect of distance between two vertically arranged inclusions on fatigue crack initiate depends on the depth of inclusions.

Automated summary

The microstructure of materials plays a crucial role in crack initiation of rolling contact fatigue. In the case of tapered roller bearings, the inhomogeneous characteristic of the material is considered. Through the simulation of random material grain distribution using Voronoi graph, a Voronoi finite element model for rolling contact fatigue is developed. By conducting numerical analysis, the effect of material microstructure inhomogeneity on fatigue crack initiation life is studied. The research shows that smaller grain size makes it more difficult for fatigue cracks to appear, while a larger difference of elasticity modulus between non-metallic inclusions and matrix material has a greater impact on fatigue life of crack initiation. Angular and sharp non-metallic inclusions reduce fatigue life more than rounded shape inclusions.