Abstract：The cutting process produces large stress, strain and strain rate, which are much higher than those in traditional mechanical tests, including Split-Hopkinson pressure bar test. Therefore, a new method is proposed to identify the constitutive parameters of metal materials. This method is based on high-resolution in-situ imaging and digital image correlation technique (DIC), combined with analytical algorithm optimization, the optimal parameters of materials constitutive model have been identified. It is especially suitable for identifying constitutive parameters in the case of large strain and strain rate. In-situ imaging technique is used to perform orthogonal turning experiments on 45 steel (AISI 1045), and the strain and strain rate fields in the primary shear zone (PSZ) are obtained using DIC technique. Then, the stress field is calculated based on the constitutive equation. Stress integrations in the PSZ shear plane are obtained and matched with the component of the cutting force measured by the dynamometer projected onto the shear plane, and the optimal constitutive parameter is identified by performing the optimization of the solution. Finally, the feasibility and effectiveness of the proposed method are verified by comparing the results of finite element simulation using the identified constitutive parameters with the experimental results.
2021, 
