Finite Element Analysis of Hard and Soft Tissue Contributions to Thoracic Response: Sensitivity Analysis of Fluctuations in Boundary Conditions

The principle cause of 30% of road traffic deaths is thoracic trauma. In order to validate anthropometric test device mechanical response and numerical human models and elucidate injury mechanisms, force-deflection corridors for various thoracic loading conditions have been developed. The variability inherent in biological experimentation results in a corridor, instead of a single response characteristic. Both extrinsic and intrinsic factors create such variability. Individual difference among human subjects, such as body geometry and material property differences, are associated with intrinsic factors. Loading fluctuations and experimental test supporting conditions are examples of extrinsic sources of variability. Intrinsic factors have been considered in recent studies, such as material-level rib response, which are modifiable over a limited internal range. An example is use of finite element (FE) modeling to fit gross overall thoracic response corridors. Uncertainty is usually not considered in such studies due to extrinsic factors. The authors discuss using a thorax FE model to estimate how selected extrinsic factors contribute to response corridor uncertainty. Analysis of sensitivity of twelve response corridors was performed relative to test fixture, loader, and thorax positioning. Reasonable experimental uncertainty ranges for thorax orientation and loader angle and location were established, and intact, denuded, and eviscerated tissue states with hub, distributed belt, single diagonal belt, and double diagonal belt loader were analyzed for response variability. Of all variables studied, force-deflection response, responsible for effective stiffness increases and decreases of up to 20%, is most greatly affected by thorax orientation. The extrinsic contribution was isolated from the corridor through simulation work and model deficiencies and refinements, with the potential to improve model accuracy, particularly soft tissue and costal cartilage, were indicated.

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  • English

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  • Accession Number: 01046239
  • Record Type: Publication
  • ISBN: 139780768018295
  • Files: TRIS
  • Created Date: Apr 10 2007 7:24PM