抄録
A series of fatigue tests have been made to determine experimentally the size and notch effects of hollow specimens on the fatigue strength in reversed torsion. The hollow specimens were carefully machined out from one stock, composed of hot drawn low carbon steel pipe with 0.14%C, nearly satisfying the condition of geometrical similarity, that is, with their external and internal diameters of 41 and 31mm respectively for the large testpieces, and 8 and 6mm for the small. For the sake of comparison some solid cylindrical specimens were also prepared each with diameter of 8mm. Holes of several sizes were drilled reaching transversally to the central axis of the specimens. The material has been experimentally examined regarding the homogeneity of its quality with its static mechanical properties. Its agreement with the specimens annealed in vacuum has been established. In this experiments, size effect has been hardly observed in the testpieces of geometrically similarisize, and the notch effect of the drill holes has been determined as 1.6 and 2.7, for the diametral ratio of the drill holes and the specimens of 0.06 and 0.25, respectively.
