Material-Point Simulation to Cavity Collapse Under Shock

TL;DR

This paper uses the material-point-method to analyze cavity collapse under shock, revealing how shock strength influences collapse symmetry, jet formation, and hot spot distribution, with implications for material erosion and explosive ignition.

Contribution

It introduces a detailed simulation of cavity collapse under shock using the material-point-method, highlighting effects of shock strength and symmetry not captured by fluid models.

Findings

Strong shock leads to jet creation during cavity collapse.

Weak shock results in nearly isotropic cavity collapse.

Collapse history affects hot spot distribution.

Abstract

The collapse of cavities under shock is a key problem in various fields ranging from erosion of material, ignition of explosive, to sonoluminescence, etc. We study such processes using the material-point-method developed recently in the field of solid physics. The main points of the research include the relations between symmetry of collapsing and the strength of shock, other coexisting interfaces, as well as hydrodynamic and thermal-dynamic behaviors ignored by the pure fluid models. In the case with strong shock, we study the procedure of jet creation in the cavity; in the case with weak shock, we found that the cavity can not be collapsed completely by the shock and the cavity may collapse in a nearly isotropic way. The history of collapsing significantly influences the distribution of "hot spots" in the shocked material. The change in symmetry of collapsing is investigated. Since we use the Mie-Gr% \"{u}neisen equation of state and the effects of strain rate are not taken into account, the behavior is the same if one magnifies the spatial and temporal scales in the same way.