Identification of Constitutive Material Model Parameters for High-Strain Rate Metal Cutting Conditions Using Evolutionary Computational Algorithms

Abstract

Advances in plasticity-based analytical modeling and finite element methods (FEM) based numerical modeling of metal cutting have resulted in capabilities of predicting the physical phenomena in metal cutting such as forces, temperatures, and stresses generated. However, accuracy and reliability of these predictions rely on a work material constitutive model describing the flow stress, at which work material starts to plastically deform. This paper presents a methodology to determine deformation behavior of work materials in high-strain rate metal cutting conditions and utilizes evolutionary computational methods in identifying constitutive model parameters. The Johnson–Cook (JC) constitutive model and cooperative particle swarm optimization (CPSO) method are combined to investigate the effects of high-strain rate dependency, thermal softening and strain rate-temperature coupling on the material flow stress. The methodology is applied in predicting JC constitutive model parameters, and the results are compared with the other solutions. Evolutionary computational algorithms have outperformed the classical data fitting solutions. This methodology can also be extended to other constitutive material models.

Keywords:

• Constitutive material models
• High-strain rate plasticity
• Metal cutting
• Particle swarm optimization

Notes

*Reference strain-rates are 7500 s⁻¹ for AISI 1045 and 10500 s⁻¹ AA 6082-T6 [11], 2000 s⁻¹ for Ti6Al4V [12].

*Reference strain-rates are 7500 s⁻¹ for AISI 1045 and 10500 s⁻¹ AA 6082-T6 [11], 1500, 2000, 2500 s⁻¹ for AISI 4340 [13], 0.0001, 0.1, 2150 s⁻¹ for Ti6Al4V [14].