Growth da/dN to
ASTM E647 & BS 6835 performs a range of fatigue crack growth tests on
any shape specimen
The purpose of this
test is to determine fatigue crack growth rates in materials from near
threshold (crack arrest) to unstable levels of stress intensity (K).
The most common
test piece geometries used are the compact tension (CT), centre cracked
tension (MT), 3 point bend (SENB3) and 4 point bend (SENB4) specimens.
However, any geometry specimen may be used provided that stress intensity
(K) calibrations are available.
measurement is required and this is normally achieved using AC or DC
potential drop equipment, or the changing compliance technique using a
crack opening displacement (COD) gauge.
A sharp defect or
precrack is generally introduced into the specimen prior to the crack
growth test; this can be done within DMG's precrack software (see separate
For further information, please click here.