Structural Influence on the Mechanical Response of Adolescent Gottingen Porcine Cranial Bone

Abstract

Bone specimens were dissected from the crania of adolescent Gttingen minipigs. These specimens were small cubes that contained the entire thickness of the skull. The microstructure of these skull specimens was quantified at the micron-length scale using micro-computed tomography (CT). The skull microstructure demonstrated a clear porosity dependence on location along the skull thickness; the skull was highly porous near the skin-side surface and became less porous as location approached the brain-side surface. The skull specimens were then loaded in quasi-static compression to measure their mechanical response. The surface strain distribution on the specimen face was measured during loading using digital image correlation (DIC). The 2-D strain field formed a gradient of iso-strain bands along the thickness (depth) dimension from the skin-most to brain-most sides of the skull. The specimen was modeled by discretizing the depth dimension into a series of layers. The DIC measurements were then used to derive the stress-strain response of each layer. The initial portion of this response was used to calculate depth-dependent moduli for each layer. These localized mechanical properties were related with structural parameters calculated from the high-resolution images. The model enabled the prediction of local moduli based on morphological parameters measured with CT and provided an estimation of the tissue modulus of the cranial bone.

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Document Details

Document Type
Technical Report
Publication Date
Oct 01, 2016
Accession Number
AD1020449

Entities

People

  • C. A. Gunnarsson
  • Stephen L. Alexander
  • Tusit Weerasooriya

Organizations

  • United States Army Research Laboratory

Tags

Communities of Interest

  • Air Platforms
  • Counter WMD
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Adolescents
  • Apparent Density
  • Brain Injuries
  • Compression
  • Digital Images
  • High Resolution
  • Measurement
  • Mechanical Properties
  • Mechanics
  • Microstructure
  • Modulus Of Elasticity
  • Skull
  • Thickness
  • Three Dimensional
  • Tomography
  • Two Dimensional
  • X-Ray Computed Tomography

Readers

  • Mechanical Engineering/Mechanics of Materials.
  • Medical Imaging.
  • Wave Propagation and Nonlinear Chaotic Dynamics.