Modeling Strain Hardening of Metallic Materials with Sigmoidal Function Considering Temperature and Strain Rate...

Area of Science:

• Materials Science
• Mechanical Engineering
• Computational Mechanics

Background:

• Plastic strain hardening is crucial for predicting material behavior under stress.
• Existing models often struggle to accurately capture temperature and strain rate dependencies.
• Anisotropic and strength differential effects present challenges in material modeling.

Purpose of the Study:

• To develop and validate a sigmoidal hardening law incorporating temperature and strain rate effects.
• To compare the proposed model's effectiveness against established hardening laws.
• To enhance the prediction accuracy of plastic deformation in metallic materials.

Main Methods:

• A sigmoidal function was employed to model plastic strain hardening.
• Temperature effects were integrated using a simplified Arrhenius model.
• Strain rate effects were incorporated via a modified Johnson-Cook model.
• An asymmetric yield criterion was coupled with the hardening law.
• Model calibration and validation used uniaxial and biaxial flow curves for various metallic alloys.

Main Results:

• The sigmoidal hardening law effectively describes plastic strain hardening.
• The model accurately predicts material behavior under combined temperature and strain rate variations.
• Integration with an asymmetric yield criterion addresses anisotropy and strength differential effects.
• Validation demonstrated the model's broad applicability across different metallic alloys.

Conclusions:

• The proposed sigmoidal hardening law offers a precise and versatile approach to modeling plastic deformation.
• The model provides improved predictive capabilities for metallic materials under complex loading and environmental conditions.
• This work advances constitutive modeling for engineering applications involving metallic alloys.