Bounds on the hydrostatic plastic strength of voided polycrystals and implications for linear-comparison homogenization techniques

M. I. IDIART; J. E. RAMOS NERVI

COMPTES RENDUS MECANIQUE

ELSEVIER FRANCE-EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER

Lugar: Paris; Año: 2014 vol. 342 p. 25 - 31

1631-0721

A linear-comparison homogenization technique and its relaxed version are used to compute bounds of the Hashin-Shtrikman and the Self-Consistent type for the hydrostatic strength of ideally plastic voided polycrystals. Closed-form analytical results are derived for isotropic aggregates of various cubic symmetries (fcc, bcc, ionic). The impact of the variational relaxation on the bounds is found to be significantly larger than that previously observed in fully dense polycrystals. So much so that, quite surprinsingly, relaxed Self-Consistent bounds are found to be weaker than non-relaxed Hashin-Shtrikman bounds in some of the material systems considered.