Analytical modeling of shock wave stresses and spall caused by laser plasma in a material interface – application to paint stripping on aluminum substrates

Summary

In the present work, analytical and numerical models have been developed to calculate shock wave stresses caused by laser plasma in a material interface. The input pressure causing the shock wave has been derived from a laser-matter interaction model. The material velocity, stresses, and strains versus time in the two materials and the interface have been computed by solving the jump equations for conservation of mass and balance of momentum. The material interface has been considered as an immovable boundary while the back free surface as an unrestrained boundary. Spall fracture strength of the interface was evaluated and was used as stripping criterion. The model has been used for the fast computation of interfacial stresses causing paint stripping on aluminium substrates and the subsequent fast assessment of stripping initiation. An explicit finite element model combined with the cohesive zone modelling method and a spall fracture model have been developed. These models have been compared to each other in terms of time, accuracy and input properties demand and to the experimental results.

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