Modelling of rupture ductility of metallic materials over wide ranges of temperatures and loading conditions, part II: comparison with strain energy-based approach

ABSTRACT

In addition to strain, inelastic strain energy is often used for estimating damage due to inelastic deformation. In order to compare with the approach using inelastic strain, rupture strain energy density was modelled as a function of temperature and strain rate or energy density rate for four materials, using similar equations. It was found that these energy-based approaches provide an equally good performance in modelling the temperature- and strain rate-dependency of rupture energy density as in the strain-based approach. Using the equivalent stress vs. equivalent strain rate relations developed in the companion paper simultaneously, the rupture energy density under various conditions could be estimated with a reasonable accuracy. It was also found that the employment of a common value for the thermal activation energy for all materials does not deteriorate the quality of modelling significantly thus allowing a direct comparison of the characteristics of different materials on the same ground.

KEYWORDS:

• Strain energy density
• ductile fracture
• creep rupture
• temperature-dependency
• strain rate-dependency

Disclosure statement

No potential conflict of interest was reported by the author.