Numerical analysis of interaction between microbubble and elastic microvessel in low frequency ultrasound field using fluid solid interaction method

The interaction between microbubble and elastic microvessel wall has been hypothesized to be important in the mechanisms of therapeutic ultrasound applications. In this study, a 2D axisymmetric finite element numerical model is established to study the interaction between elastic microvessel wall and oscillating microbubble in low frequency ultrasound field using fluid solid interaction method. The numerical results show that the bubble oscillation induces the vessel wall dilation and depression. The maximum von Mises stress of the midpoint on the inner vessel wall could reach 235kPa under PNP 0.2MPa. When the bubble collapses, the von Mises stress is even bigger than that in the expansion phase. The maximum von Mises stress of the midpoint on the inner vessel wall could reach 235kPa under PNP 0.2MPa. When the bubble collapses, the von Mises stress is even bigger than that in the expansion phase. Noticeably, the circumferential stress becomes compressive during collapsing quickly with the magnitude much larger than the maximum tension value. It is possible that the rapid compression stress effect during bubble collapse plays important role in mechanics of microvessel wall endothelial lining disruption due to microbubble cavitation rather than the tensile effect.