Optimization on the Johnson-Cook parameters of Ti-6Al-4V used for high speed cutting simulation

Abstract

The Johnson-Cook (J-C) parameters obtained from the conventional mechanical tests are usually adopted directly for the high-speed cutting simulations. However, the conventional J-C parameters can not describe the exact plastic deformation under the coupling effect of large strain and high strain rate occurred in high speed cutting. In this paper, the response surface approximation method was used to optimize the Ti-6Al-4V's J-C parameters for high speed cutting simulation, and the experimental results obtained from our previous work were further adopted to validate the optimized parameters. The simulated chip size error obtained at the cutting speed of 15 m/s could reduce from 16% with using the conventional J-C parameters to 8% with using the optimized J-C parameters. Furthermore, the simulated chip morphologies achieved based on the optimized J-C parameters were compared with the experimental results with cutting speed ranging from 0.05 m/s to 86.5 m/s. The results show that the simulated chip morphologies could give good agreements with the experimental results, and the chip morphology transitions can be well predicted with using the optimized J-C parameters.