Numerical studies of cavitation erosion on an elastic-plastic material caused by shock-induced bubble collapse

We present a study of shock-induced collapse of single bubbles near/attached to an elastic-plastic solid using the free-Lagrange method (FLM), which forms the latest part of our shock-induced collapse studies. We simulated the collapse of 40 um-radius single bubbles near/attached to a rigid and aluminium walls by a 60 MPa-lithotripter shock for various scenarios based on bubble-wall separations, and the collapse of a 255 um-radius bubble attached to an aluminium foil with a 65 MPa-lithotripter shock. The coupling of the multi-phases, compressibility, axisymmetric geometry and elastic-plastic material model within a single solver has enabled us to examine the impingement of high speed liquid jets from the shock-induced collapsing bubbles, which imposes an extreme compression in the aluminium that leads to pitting and plastic deformation. For certain scenarios, instead of the high speed jet, a radially inwards flow along the aluminium surface contracts the bubble to produces a ‘mushroom shape’. This work provides methods for quantifying what parameters (e.g. bubble sizes and separations from the solid) might promote or inhibit erosion on solid surfaces