Ratcheting evaluation of additively manufactured 4043 aluminum samples through a combined isotropic–kinematic hardening framework

Abstract

The present study evaluated the ratcheting behavior of additive manufactured 4043 aluminum alloy by coupling the Ahmadzadeh–Varvani (A–V) kinematic hardening rule with the isotropic hardening rule of Lee–Zaverl (L–Z). The L–Z description expanded the yield surface while the A–V model translated yield surface in deviatoric stress space. Materials coefficients Q and b in the L–Z model were, respectively, determined to address expansion of yield surface and its rate. Coefficients C and ${\gamma }_{1}$ in the A–V model were determined through consistency condition at which predicted hysteresis loops coincided with those experimentally obtained. The coefficient ${\gamma }_{2}$ was determined from the close agreement of the predicted and measured ratcheting strain data plotted over loading cycles. Increments of backstress were plotted versus stress cycles demonstrating a gradual decay as the number of stress cycles increased through the involvement of an internal variable $\overline{{\varvec{b}} }$. Ratcheting curves and their corresponding hysteresis loops predicted based on the isotropic–kinematic framework were found in good agreements with those of experimental values.