Parameter identification of constitutive model at high strain rate for TC17 titanium alloy under shock wave induced by nanosecond pulsed lasers

On the basis of the Johnson-Cook (J-C) constitutive model, one parameter identification method based on the finite element model and the modified Levenberg-Marquard (L-M) algorithm is proposed. When TC17 materials are under laser shocking with different parameters and processes, the residual stress field distribution at high strain rate is obtained and the dynamic response curve at intermediate strain rate is obtained by the Hopkinson pressure bar. The above two test results are taken as the targets of identification. The response curve at low strain rate is introduced as a constraint condition and the J-C constitutive model parameters at high strain rate are identified. The comparison between the experimental and calculated results indicates that the parameters obtained by identification can be used to accurately describe the dynamic response law of TC17 titanium alloys at high strain rate and to predict the residual stress field distribution of materials under laser shocking.