Multiscale Damage to Axons Under Dynamic Mechanical Loading Including Cavitation
Abstract
Most of military Traumatic Brain Injuries (TBIs) occur when the head experiences an external impact or sudden acceleration and deceleration due to blast exposure. Depending on the blast origin and soldierÕs proximity, brain injury can be governed by direct pressure propagation (primary blast: overpressure or shockwave), impact (secondary blast: penetrating or closed), inertial forces (tertiary blast: shear diffuse acceleration-deceleration injuries), or by cavitation (bubble formation in fluid media). In case of non-penetrating head impact, TBIs occur mostly by overpressure/shockwave propagation, shear diffusion or by cavitation. Recent studies suggest that materials that constitutes brain are very weak in resisting shear deformation and strain rate dependent (viscoelastic). Yet, we currently have an incomplete understanding of the role of overpressure, shear diffusion and cavitation on brain injury propagation, thresholds and pathology, primarily because brain is a complex material with characteristic features span across a wide range of length scales (nanoscale to macroscale), and where injury nucleates at different scales. The long term objective here is to link blast-induced traumatic brain injury (TBI) with multiscale, multiphysics damage evolution in the brain using experimentally verifiable computations and simulations. The short term goal is to conduct modeling and simulation to correlate dynamic mechanical loading to damage, specifically due to cavitation, in sub-axonal components, axons, and aggregates of axons in extracellular matrix. In the present effort, it will be possible to determine the effects of cavitation bubbles on the basic structure of the axon and, if warranted, future efforts can add in additional structural components such as neurofilaments (intermediate filaments) and microfilaments as well as functional components such as the synaptic vesicles that traffic along the microtubules.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jun 10, 2016
- Source ID
- N000141612142
Entities
People
- Ashfaq Adnan
Organizations
- Office of Naval Research
- United States Navy
- University of Texas at Arlington