Research on Modification of J-C Constitutive Model for Dynamic Mechanical Behavior of Ti60 Titanium Alloy

To investigate the dynamic mechanical behavior of Ti60 titanium alloy and establish a reasonable constitutive model, the quasi-static tensile and dynamic impact tests were conducted using a universal testing machine and a split Hopkinson pressure bar(SHPB) apparatus. Based on the obtained stress-strain curves, the parameters of the original Johnson-Cook(J-C) constitutive model were calibrated, and its fitting accuracy and the influencing factors were examined.Considering the characteristics of the flow stress behavior, a modified J-C constitutive model that accounts for the coupling effects of strain, strain rate, and temperature was developed, and its parameters were determined. A comparative analysis was performed between the predicted values from the modified model and the experimental data. The accuracy of the established modified model was evaluated using two statistical parameters: the correlation coefficient(R) and the average absolute relative error(AARE). The results indicate that the established modified J-C constitutive model achieves a correlation coefficient R of 0.9922 and an AARE of 1.48%. The modified model which incorporates the coupling of stress, strain, and temperature, can effectively predict the flow stress behavior of Ti60 titanium alloy.