Th. Hyde et al., PREDICTION OF CREEP FAILURE IN AEROENGINE MATERIALS UNDER MULTIAXIAL STRESS STATES, International journal of mechanical sciences, 38(4), 1996, pp. 385
The creep and creep rupture behaviour of two, significantly different,
aeroengine materials, namely a nickel-base superalloy at 700 degrees
C and a high temperature titanium alloy at 650 degrees C, were studied
. Experimental creep tests were conducted on uniaxial specimens and ax
isymmetric notched bars under constant tensile loads conditions. From
the uniaxial creep test results, a creep continuum damage model was es
tablished for each of the materials. The skeletal point stress approac
h was used to obtain the approximate creep rupture stress criterion in
the multi-axial generalization of the creep continuum damage models.
This approximation was cross-checked using axisymmetric Finite Element
(FE) analyses in a trial and error procedure. Multi-axial creep conti
nuum damage models were then used in further FE creep analyses to pred
ict the creep rupture times in specimens subjected to different tensil
e loads. The FE predictions of the rupture times in these notched spec
imens were found to be in good agreement with the experimental results
for the nickel-base superalloy (Waspaloy) at 700 degrees C and the ti
tanium alloy (IMI834) at 650 degrees C.