Development of fatigue crack growth in real structures

In this contribution several examples for fatigue crack growth in machines and components will be shown. The reason for failures e.g. can be found in misconstructions, inappropriate fatigue strength calculations as well as material and manufacturing imperfections. Fatigue crack growth as consequence of service loads depends on many different contributing factors. The magnitude and chronological sequence of the loading as well as its type and direction and such the normal and shear stress distribution in a structure have major influence. Not only the crack velocity (crack growth rate) but also the crack configuration (crack path) can be determined by means of fracture mechanics. With the help of numerical simulations fatigue crack growth in three-dimensional structures can either be predicted or at least be explained for already existing failures.