Investigation of acoustic-plastic constitutive modeling based on Johnson–Cook model and numerical simulation application

Abstract

In this paper, a modified acoustic-plastic Johnson–Cook model for Ti–45Nb alloy was established, which can be used to reveal the metallic deformation behavior under ultrasonic vibration-assisted (TUV) forming. First, the experiments of traditional compression and TUV compression were carried out, the influence of vibration amplitude on yield strength, strain hardening coefficient and index, and strain rate hardening coefficient. The yield strength reduction is caused by the acoustic softening effect. The yield strength and strain hardening coefficient present a negative correlation with amplitude increase, the strain hardening index and strain rate hardening coefficient present a positive correlation with amplitude increase. Further, the accuracy of the developed constitutive model was quantitatively identified, the relative coefficient is as high as 0.954, the mean absolute percentage error less than 5.42%. On this basis, a user-defined subroutine was developed to implement the numerical simulation of the TUV forming processes using the finite element method, the results of numerical simulation and experiment are in good agreement, and prediction accuracy is as high as 95.25%. Therefore, the developed constitutive model can be well revealed the material deformation behavior and provides an application guide.