Coupled interaction between a cavitation bubble and an elastoplastic wall

This study examines the evolution of a cavitation bubble near an elastoplastic wall and the resulting wall response. A tightly coupled fluid–structure interaction framework is developed by integrating a volume-of-fluid multiphase flow model with a bilinear elastoplastic constitutive formulation. This approach enables the simulation of cavitation bubble expansion, contraction, jet formation, and wall deformation across a range of stand-off distances λ. Experimental comparisons confirm the accuracy and reliability of the numerical model. The results show that an increase in λ causes the cavitation bubble jet to switch from a wall-oriented direction to one pointing away from the wall. Correspondingly, the dominant wall deformation mechanism shifts from jet-impact loading at small λ to pressure difference–driven deformation at larger λ. Under strong near-wall confinement, the wall exhibits pronounced stress concentration and plastic strain near its center, whereas at larger λ, the applied load becomes more spatially distributed, and the peak stress appears later in time. Clear timing differences in pressure and velocity peaks during cavitation bubble collapse are observed across the tested λ values. Furthermore, the equivalent plastic deformation decreases with increasing λ, highlighting the intrinsic buffering capability of elastoplastic materials against cavitation bubble-induced loading. Overall, the study provides insight into the coupled dynamics between cavitation bubbles and elastoplastic boundaries and offers guidance for improving the reliability of engineering systems, as well as the precision of biomedical applications.