Premium
FATIGUE DAMAGE IN TWO‐STEP LOADING OF 316L STEEL II. SHORT CRACK GROWTH
Author(s) -
Vašek A.,
Polák J.,
Obrtlíak K.
Publication year - 1996
Publication title -
fatigue and fracture of engineering materials and structures
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.887
H-Index - 84
eISSN - 1460-2695
pISSN - 8756-758X
DOI - 10.1111/j.1460-2695.1996.tb00955.x
Subject(s) - crack closure , crack growth resistance curve , materials science , growth rate , crack tip opening displacement , composite material , amplitude , fracture mechanics , paris' law , structural engineering , mathematics , geometry , engineering , optics , physics
— The evolution of the surface crack distribution in single‐step and two‐step plastic strain amplitude controlled cycling was studied. The frequency of crack occurrence and total crack density were evaluated together with crack growth rates of the largest cracks. The crack density increases, reaches a maximum, and then decreases during fatigue life. The maximum value of crack density partitions the whole life into a “crack generation period” and a “crack propagation period”. In the first period the crack growth rate is approximately constant and is determined by the applied plastic strain amplitude. The crack growth rate increases with crack length in the second period, but is basically determined by the crack growth rate in the “crack generation” period. Hence the crack growth rate in the “crack generation” period is the life determining factor.