ORCID Identifier(s)

0000-0002-0335-3376

Graduation Semester and Year

2015

Language

English

Document Type

Thesis

Degree Name

Master of Science in Aerospace Engineering

Department

Mechanical and Aerospace Engineering

First Advisor

Ashfaq Adnan

Abstract

Traumatic brain injury (TBI) accounts to almost one fifth of total fatal injuries. Even though there are various mechanisms hypothesized for the causes leading to TBI, diffuse axonal injury (DAI) is found to be the most observed criterion. The reason for axonal failure in DAI has been studied extensively using experimental and computational models. It was found that axons behave like viscoelastic materials, thus exhibiting rate dependent behavior under loading. This viscoelastic behavior of axons is believed to drive the failure of axons and its substructures. It was observed that axon failure is caused by failures and distortions in axonal cytoskeleton, particularly Microtubule-Tau protein assembly.Inspired by the previous work, we have developed modified shear lag model to predict axonal damage under dynamic loading conditions. Opposed to previous work where only tau proteins were considered viscoelastic, we have assumed both microtubules and tau proteins to be viscoelastic and modeled them using a two parameter kelvin model. We have then studied the effect of strain rate on viscoelastic response of microtubule –tau protein assembly. We have attempted to determine a phase diagram in terms of loading rate and applied strain to isolate the two possible axonal deformation modes, namely microtubule failure due to excessive stretch and reversible microtubule sliding due to tau protein stretch

Keywords

Microtubules, Viscoelastic, TBI

Disciplines

Aerospace Engineering | Engineering | Mechanical Engineering

Comments

Degree granted by The University of Texas at Arlington

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