Characterisation and modelling of anisotropic hardening behaviour of cubic and hexagonal close packed polycrystalline metals

ABSTRACT

In this study, anisotropic non-proportional hardening behaviour of the sheet metals with different crystalline structures is investigated. The investigated materials particularly exhibit the Bauschinger effect and complex transient hardening behaviour during loading path change. Furthermore, the finite element simulations are carried out to evaluate the performance of the distortional and multi-surface-kinematic hardening models in flow stress prediction under loading path change. Both models can well reproduce the measured anisotropic hardening, but the distortional hardening concept shows better predictive capability for flow stresses. The improved accuracy of the flow stress prediction with the distortional hardening model compared to the kinematic hardening is attributed to its flexibility in distortion of the yield surface following microstructure deviator independent on the initial yield surface. In contrast, the initial size of the yield surface in the kinematic hardening significantly affects the determination of the re-yielding stress at load reversal.

KEYWORDS:

• Distortional hardening
• Bauschinger effect
• plastic deformation
• kinematic hardening

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

Myoung-Gyu Lee appreciates support from the NRF of the Korean government (Grant No. 2022R1A2C2009315), and MOTIE of Korea (Project No.1415185590, 20022438). Jinwoo Lee is grateful for the support of the “Regional Innovation Strategy” (RIS) through the National Research Foundation of Korea (NRF), funded by the Ministry of Education (MOE) (2021RIS-003).

Notes on contributors

Jinwoo Lee

Jinwoo Lee is an Assistant Professor in the School of Mechanical Engineering, University of Ulsan, Republic of Korea.

Hyung-Rim Lee

Hyung-Rim Lee is a post-doc fellow in the Department of Materials Science and Engineering, Seoul National University, Republic of Korea.

Myoung-Gyu Lee

Myoung-Gyu Lee is a Professor in the Department of Materials Science and Engineering, Seoul National University, Republic of Korea.