Premium
SPECIMEN SIZE DEPENDENCE OF LOW FREQUENCY FATIGUE TESTS IN HIGH‐PRESSURE HYDROGEN
Author(s) -
Roebuck B.
Publication year - 1983
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.1460-2695.1983.tb00334.x
Subject(s) - materials science , fracture mechanics , stress intensity factor , fracture (geology) , diffusion , paris' law , range (aeronautics) , yield (engineering) , crack closure , structural engineering , hydrogen , composite material , mechanics , engineering , thermodynamics , chemistry , physics , organic chemistry
— Fatigue data required for estimates of cracked component lifetimes are conventionally obtained by cyclic loading of specimens manufactured to a specific geometry. Crack growth in the specimen results in an increase in the stress intensity factor range and crack growth curves are calculated from the variation of crack length with time. An environmental fatigue study of the effect of high pressure hydrogen on the low cycle fatigue of a medium strength steel has shown that, due to effects of elapsed time in the environment and effects of specimen size, in certain circumstances this procedure may not yield geometry‐independent results which can be applied with confidence to cracked components. It is concluded that to obtain useful crack growth data in cases where fracture is influenced by diffusion or other strongly time dependent processes might require a modified approach to fracture mechanics testing procedures.