Institute of Physics of Materials AS CR, v. v. i. > Projects > The effect of free surface on fatigue crack growth

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The effect of free surface on fatigue crack growth

Anotace

The nature of the crack tip singularity changes in the vicinity of a corner point where a crack front intersects a free surface. Due to the fact, crack propagation in 3D-structures cannot be generally reduced to a series of plane problems along the crack front edge and corner point singularities have to be taken into the consideration. There are two types of stress singularity (the edge and the corner stress singularity) and both influence the fatigue crack propagation behaviour. Suggested project solves this problem on the base of linear elastic fracture mechanics. The fatigue crack is described by the generalised stress intensity factor. Presumptive results make it possible quantitative description of crack propagation rate for crack influenced by the free surface. The numerical analysis is performed by finite element method. The result makes an estimation of residual fatiguelife of 3D-structures more believable.