High-strain-rate mechanical constitutive modeling with computational parameters

Abstract

Mechanical constitutive relationships characterize the strain response of materials under external loading, laying the foundation for optimizing material performance and guiding engineering design. However, existing modeling methods for mechanical constitutive relationships, especially for high strain rate (HSR) loading, often rely on fitted experimental data and fail to comprehensively capture the underlying physical mechanisms. In this work, we propose a mechanical constitutive modeling with computational parameters (MCMCP) method suitable for HSR loading conditions, which establishes a quantitative link between the microstructure of materials and their macroscopic mechanical properties by fully integrating fundamental physical principles. This method couples the thermally activated dislocation unpinning mechanism with the phonon drag effect to accurately describe dislocation velocity and the influence of strain rate on plastic behavior. Additionally, a multi-mechanism coordinated strength-solving framework is introduced. It predicts the slip-twinning transition and quantitatively evaluates the contributions of various strengthening mechanisms. By incorporating microstructural evolution information, the material’s flow stress-strain response can also be predicted. Validation against simulations of pure metals and alloys confirms the effectiveness of the proposed method. This work not only enhances the understanding of micro-scale physical mechanisms for mechanical behavior but also provides a practical tool for predicting the mechanical properties under HSR loading.