Ingrid Delyová^1,, Peter Sivák¹

The whole structures, mostly the structural nodes or elements work in time-varied stress instead of the static one. The stress concentrators are such changes of shape of mechanical part which evoke the changes of force flow. They influence the stress which loads this part. The risk of fatigue damage concerns structural components, structural knots and even whole structures subjected to random loading. This can initiate the accumulation of fatigue damage in critical points of the structure, growth and spreading of fatigue cracks and, eventually, fatigue fracture. Final failure of structural components may have fatal consequences. Damage and fatigue failure may occur due to a combination of cyclical stress and improper technology for producing a structural element, e.g. during welding. These failures are documented on the example of the holder of a crusher moving knife and of the turbine rotor shaft.

fatigue crack, fatigue damage, loading, stress concentration factor