0

Full Content is available to subscribers

Subscribe/Learn More  >

High Rate Impact to the Human Calcaneus: A Micromechanical Analysis

[+] Author Affiliations
Rebecca A. Fielding, Reuben H. Kraft, Christopher D. Kozuch

Penn State University, State College, PA

X. G. Tan, Andrzej J. Przekwas

CFD Research Corporation, Huntsville, AL

Paper No. IMECE2014-38930, pp. V003T03A009; 8 pages
doi:10.1115/IMECE2014-38930
From:
  • ASME 2014 International Mechanical Engineering Congress and Exposition
  • Volume 3: Biomedical and Biotechnology Engineering
  • Montreal, Quebec, Canada, November 14–20, 2014
  • Conference Sponsors: ASME
  • ISBN: 978-0-7918-4646-9
  • Copyright © 2014 by ASME

abstract

An “underbody blast” (UBB) is the detonation of a mine or improvised explosive device (IED) underneath a vehicle. In recent military conflicts, the incidence of UBBs has led to severe injuries, specifically in the lower extremities The foot and ankle complex, particularly the calcaneus bone, may sustain significant damage. Despite the prevalence of calcaneal injuries, this bone’s unique properties and the progression of fracture and failure have not been adequately studied under high strain rate loading. This research discusses early efforts at creating a high-resolution computational model of the human calcaneus, with primary focus on modeling the fracture network through the complex microstructure of the bone and creating micromechanically-based constitutive models that can be used within full human body models. The ultimate goal of this ongoing research effort is to develop a micromechanics-based simulation of calcaneus fracture and fragmentation due to impact loading. With the goal of determining the basic mechanisms of stress propagation through the internal structure of the calcaneus, a two-dimensional model was employed for preliminary simulations with a plane-strain approximation. In this effort, a cadaveric calcaneus was scanned to a resolution of 55 μm using an industrial micro-computed tomography (microCT) scanner. A mid-sagittal plane slice of the scan was selected and post-processed to generate a 2D finite element mesh of the calcaneus that included marrow, trabecular bone, and cortical bone elements. The calcaneus was modeled using two-dimensional quadratic plane strain elements. A fixed boundary condition was applied to the portion of the calcaneus that, in situ, would be restrained by the talus. A displacement of 1.25 mm was applied to the heel of the calcaneus over 5 ms. In a typical result, following impact, the strain and stress are propagated throughout the cortical shell and then began to radiate into the bone into the bone along the trabeculae. Local stress concentrations can be observed in the trabecular structure in the posterior region of the bone following impact. Upon impact, cortical and trabecular bone show different stresses of 13MPa and 1 MPa, respectively, and exhibit complex high frequency responses. Observed results may offer insight into the wave interactions between the different materials comprising the calcaneus, such as impedance mismatch and refraction. Pore pressure in the marrow may be another important factor to consider in understanding stress propagation in the calcaneus.

Copyright © 2014 by ASME

Figures

Tables

Interactive Graphics

Video

Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In