Theoretical modeling of non-spherical inertial cavitation for anisotropic soft matter rheometry
Abstract
A key impediment to predictive modeling and simulation of the response of the human body to blunt-impact and blast loading is the high-strain-rate on stitutive behavior of biological tissues, which are required as input but remain a source of uncertainty. Therefore, there is a need for improved mechanical characterization of biological tissues andt issue phantom materials over a broad range of strain rates. To this end, a new soft-material characterization technique has been recently developed using measurements of the dynamics of isolated bubbles generated by laser or acoustic pulses, called Inertial Microcavitation Rheometry (IMR). Using high-speed imaging of the bubble dynamics along with an isotropic theoretical cavitation modeling framework provides a route to high-strain-rates of material characterization, and this approach has been shown to be able to discern mechanical properties at previously undocumented strain-rates in materials as soft as a few kPa. However, characterizing the material properties of soft, tissue-like matter in the high-strain rate regime using state-of-the-art IMR is limited to symmetric, spherical bubble collapses in homogeneous materials. The objective of this proposed work is to enable robust, high-fidelity microcavitation--based rheometry of anisotropic (specifically, transversely isotropic) materials. The work is composed of two research thrusts. The first thrust advances the state-of-the-art IMR approach to IMR version 2 (IMRv2) for high-fidelity material characterization using spherical microcavitation. IMRv2 couples a spectral collocation numerical method and comprehensive set of physics-based constitutive models for tissue-like materials with a Bayesian inference approach. IMRv2 will be able to identify the most plausible physical material model and properties and account for uncertainty in the measurements. In the second thrust, IMRv2 will be advanced to use non-spherical perturbations and-or ellipsoidal bubble shape behavior to characterize transversely isotropicmaterials. Expected outcomes of the work includeI MRv2 as a rheometry tool of soft materials with transverse isotropy and ellipsoidal viscoelastic behavior. This information may then be used in predictive digital engineering, which will enable improved strategies for mitigating and preventing injuries both in the armed forces and amongst civilians (e.g.,in sports-related injuries).
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 06, 2024
- Source ID
- FA95502310485
Entities
People
- Mauro Rodriguez
Organizations
- Air Force Office of Scientific Research
- Brown University
- Office of the Secretary of Defense