Shock-induced damage and dynamic fracture in cylindrical bodies submerged in liquid

Abstract

Understanding the response of solid materials to shock loading is important for mitigating shock-induced damages and failures, as well as advancing the beneficial use of shock waves for material modifications. In this paper, we consider a representative brittle material, BegoStone, in the form of cylindrical bodies and submerged in water. We present a computational study on the causal relationship between the prescribed shock load and the resulting elastic waves and damage in the solid material. A recently developed three-dimensional computational framework, FIVER, is employed, which couples a finite volume compressible fluid solver with a finite element structural dynamics solver through the construction and solution of local, one-dimensional fluid-solid Riemann problems. The material damage and fracture are modeled and simulated using a continuum damage mechanics model and an element erosion method. The computational model is validated in the context of shock wave lithotripsy and the results are compared with experimental data. We first show that after calibrating the growth rate of microscopic damage and the threshold for macroscopic fracture, the computational framework is capable of capturing the location and shape of the shock-induced fracture observed in a laboratory experiment. Next, we introduce a new phenomenological model of shock waveform, and present a numerical parametric study on the effects of a single shock load, in which the shock waveform, magnitude, and the size of the target material are varied. In particular, we vary the waveform gradually from one that features non-monotonic decay with a tensile phase to one that exhibits monotonic decay without a tensile phase. The result suggests that when the length of the shock pulse is comparable to that of the target material, the former waveform may induce much more significant damage than the latter one, even if the two share the same magnitude, duration, and acoustic energy.

Shock-induced bubble collapse near solid materials: effect of acoustic impedance

“…Cao et al. 2019). Furthermore, the phenomenological models proposed in § 5 can be generalized – for example, and should be functions of the bubble's stand-off distance.…”

“…Church 1989;Fovargue et al 2013). We prescribe the incident shock wave as the initial condition of the fluid governing equations, following the method described in Cao et al (2019). Away from the incident shock wave, the ambient flow velocity and hydrostatic pressure are set to v 0 = 0 mm s −1 and p 0 = 0.101 MPa, respectively.…”

“…This computational framework has been applied to simulate several fluid-structure interaction problems involving shock waves, large structural deformation, instability and fracture (e.g. Farhat et al 2013;Wang et al 2014;Chung et al 2018;Cao et al 2019). It has also been verified and validated for a few two-phase flow problems involving a bubble collapsing near a rigid wall (e.g.…”

“…2018; Cao et al. 2019). It has also been verified and validated for a few two-phase flow problems involving a bubble collapsing near a rigid wall (e.g.…”

Towards an understanding of the chemo-mechanical influences on kidney stone failure via the material point method

“…In relation to the work in [ 47 ], this damage model allows for the growth and partial damaging of sections int he stone, rather that just binary fragmentation, however in contrast to the work of Cao et. al [ 48 ], the damage model used in this work was intended for simple brittle failure with values used to approximate stone-like behavior, a more detailed damage model with experimentally derived values for stones would be more appropriate. However the advantage of using MPM in this manner allows the use of more flexible geometric and multi-material setups afforded by the Lagrangian nature of the material points.…”