Interfacial kinematics and governing mechanisms under the influence of high strain rate impact conditions: Numerical computations of experimental observations

This paper investigates the complex interfacial kinematics and governing mechanisms during high speed impact conditions. A robust numerical modelling technique using Eulerian simulations are used to explain the material response of the interface subjected to a high strain rate collision during a magnetic pulse welding. The capability of this model is demonstrated using the predictions of interfacial kinematics and revealing the governing mechanical behaviours. Numerical predictions of wave formation resulted with the upward or downward jetting and complex interfacial mixing governed by wake and vortex instabilities corroborate the experimental observations. Moreover, the prediction of the material ejection during the simulation explains the experimentally observed deposited particles outside the welded region. Formations of internal cavities along the interface is also closely resemble the resulted confined heating at the vicinity of the interface appeared from those wake and vortex instabilities. These results are key features of this simulation that also explains the potential mechanisms in the defects formation at the interface. These results indicate that the Eulerian computation not only has the advantage of predicting the governing mechanisms, but also it offers a non-destructive approach to identify the interfacial defects in an impact welded joint.