Assessment of Thorax Finite Element Model Response for Behind Armor Blunt Trauma Impact Loading Using an...

Area of Science:

• Biomechanics
• Computational modeling
• Injury prevention

Background:

• Nonperforating ballistic impacts on thoracic armor cause behind-armor blunt trauma (BABT).
• Back face deformation (BFD) is measured to assess injury potential, but its link to actual injury remains uncertain.
• Computational human body models (HBMs) offer potential for improved BABT injury risk understanding for armor design.

Purpose of the Study:

• Develop and validate a computational methodology for applying BABT loading to a human body model (HBM).
• Assess the HBM's ability to predict BABT injury metrics like rib fractures and pulmonary contusion.
• Evaluate the correlation between BFD and predicted injury severity.

Main Methods:

• A computational thorax model was enhanced with a refined finite element mesh and high-deformation rate properties.
• BABT impact boundary conditions were recreated from an epidemiological survivor database using experimental deformation data.
• A novel prescribed displacement methodology was used to apply BABT loading to the HBM.

Main Results:

• The computational thorax model demonstrated numerical stability under BABT impact.
• Predicted rib fractures and pulmonary contusion increased with BFD, back face velocity, and input energy.
• Model predictions showed good agreement with medical records for rib fractures and injury ranks in 10 cases.

Conclusions:

• The integrated HBM and BABT loading method shows promise as a tool for evaluating body armor and assessing injury risk.
• This methodology can inform future body armor design by providing a better understanding of behind-armor blunt trauma.
• Further refinement may address positional sensitivity and data limitations for improved prediction accuracy.