Pd. Nicolaou et al., SIMULATION OF THE HOT-TENSION TEST UNDER CAVITATING CONDITIONS, Metallurgical and materials transactions. A, Physical metallurgy andmaterials science, 27(10), 1996, pp. 3112-3119
A theoretical analysis of the isothermal hot-tension test under cavita
ting conditions for sheet samples was performed using a ''direct-equil
ibrium'' approach. The effects of cavity growth rate eta, initial cavi
ty volume fraction C-nu 0, strain-rate sensitivity exponent m, and spe
cimen taper on engineering stress-strain curves, strain profiles, and
failure modes were established. For a given value of m, it was predict
ed that the engineering stress-strain curves of cavitating and noncavi
tating samples are almost coincident except near failure. In fact, dur
ing quasistable deformation, the required load for a cavitating materi
al is slightly higher than that for a noncavitating material because o
f strain rate and effective area effects. Model, results also delineat
ed the competition between failure controlled by localized necking vs
fracture, the latter being defined by a critical-volume fraction of ca
vities, Specifically, at low strain-rate sensitivities m and cavity gr
owth rates eta, failure was predicted to be controlled by necking. By
contrast, at high values of m and eta, fracture prior to localized nec
king was predicted to predominate; in these cases, the cross-sectional
area at the failure site was appreciable, thus resembling a form of b
rittle fracture. The validity of the modeling approach was confirmed t
hrough the analysis of data in the literature. However, model results
did suggest that caution should be taken in the interpretation of expe
rimental data because various combinations of C-nu 0 and eta can resul
t in the same total elongation.