Experimental characterization and crystal plasticity modeling for predicting load reversals in AA6016-T4 and AA7021-T79

The detailed contribution of microstructural-level phenomena, such as dislocation structure development and annihilation, well inter-granular intra-granular backstress fields, to reverse loading behavior in metal alloys remains an area active research debate. ability predict unloading nonlinearities, the Bauschinger effect (BE), changes hardening rates during is necessary for accurate modeling deformation springback forming operations that involve strain path changes. This paper applies a recently developed elasto-plastic self-consistent (EPSC) crystal plasticity model interpret two commercially sensitive aluminum (AA): 6016-T4 7021-T79. Model calibration verification was enabled by extensive experimental campaign cyclic applied alloys. data included monotonic tension, linear followed non-linear unloading, BE, rate induce permanent softening. By considering anisotropic elasticity, density-based hardening, slip system-level stress predicted quantified different micro-scale phenomena observed behavior. capture contrasting characteristics alloys, particularly distinct softening reloading yield stresses, demonstrated its account co-dependent nature crystallographic glide sources originating from history-dependent density evolution fields. Comparison results revealed primarily driven backstress, BE governed upon load reversals are controlled strain-path density.