Application of mini specimens to high-cycle fatigue tests

Determining complete material fatigue characteristics (S-N curve) is time-consuming and very expensive. Searching for faster procedures of determining the S-N curve, one can use approximate methods which are burdened with qualitative and quantitative error. Such characteristics differ from the real experimental studies results. Yet another method involves the use of mini specimens; the specimens the dimensions of which are lower than the normative sample. It allows for performing tests using much cheaper test stands. In the specimens researched there is a size effect which is broadly discussed in the available literature. The present work offers a review of the current theoretical knowledge on the size effect. There was analysed the geometry of mini specimens applied in experimental studies. Selected works with the use of mini specimens have been reviewed. Areas have been defined in which the mini specimen application is justifiable.