ON LOCALIZATION ANALYSIS IN MULTISURFACE HYPERELASTO-PLASTICITY

Localization analysis for large strain multisurface hyperelasto-plasti city based on the multiplicative decomposition of the deformation grad ient is considered. To this end, the simple structure of the tangent o perator and the spatial localization tensor in the form of a sum of ra nk one updates is frequently exploited. For multiple active constraint s the determinant of the spatial localization tensor is shown to be co nveniently evaluated in terms of the characteristic equation of a simp le matrix containing the hardening moduli. From this equation the crit ical hardening moduli, allowing for the onset of localization under th e assumption of continuous bifurcation, may be computed. Examples of a family of hardening moduli in the anisotropic case of single crystal plasticity are discussed. Intriguing results for either latent or pure self-hardening of the slip systems are emphasized. Copyright (C) 1996 Elsevier Science Ltd.