Comparison of different spall models for simulating spallation in ductile metals

By using one-dimensional finite different hydrodynamic code coupled with four spall models, spall in ductile metal has been studied. Numerical simulation results indicate that: (1)Cut-off model and simple damage accumulation model can qualitatively describe some physical essences of spall fracture, but remain apparent discrepancies from the experimental results due to the damage influence on the material properties being neglected; However, because of using a few parameters, they are still useful to solve engineering problems without considering higher precision. (2) NAG model and FJB damage degree function model based on statistical micro-damage mechanics have a good ability of description of the process of damage evolution, and the computed free-surface velocity profiles consist with the experimental measurements very well.