Establishment and analysis of equivalent stress-equivalent strain curves of sheet metal

In order to study the applicability of equivalent stress-equivalent strain curve for different yield criteria, based on yield criteria such as Hill48, Hill79, Hill90 and Hosford, expressions of equivalent stress-equivalent strain relationship were derived, and the equivalent stress-equivalent strain curves under different loading paths for two thin metal sheets were investigated through experiments and theoretical analysis. Results show that, for these two sheets, the differences of equivalent stress-equivalent strain curves obtained based on yield criteria of Hill48, Hill79 and Hill90 under different loading paths are obvious, while there is little difference for the curves obtained based on Hosford yield criterion.