Plate materials for cardiopulmonary protection: a computational modeling study

Area of Science:

• Biomechanics
• Materials Science
• Protective Equipment Engineering

Background:

• Personal body armor, specifically ballistic protective plates (BPPs), is crucial for torso protection against high-energy impacts.
• Behind Armor Blunt Trauma (BABT) remains a significant concern, potentially damaging critical organs like the heart and lungs.

Purpose of the Study:

• To investigate the protective performance of different BPP materials and padding configurations against BABT.
• To quantify the reduction in biomechanical impact on the heart and lungs with varying BPP materials and padding thicknesses.

Main Methods:

• Utilized a validated finite element (FE) model of the torso with detailed anatomical features.
• Simulated non-penetrating impacts from a 5.56mm bullet at 500m/s on Kevlar-29, UHMWPE, and Alumina BPPs, with and without 6mm and 12mm padding.
• Validated the FE model against experimental force measurements using a life-sized torso phantom.

Main Results:

• Alumina plates demonstrated superior protection, reducing peak strain by 186% and peak stress by 229% in the heart compared to Kevlar and UHMWPE.
• The addition of padding significantly reduced strains and stresses; 12mm padding resulted in average reductions of 44% in peak heart strain and 36% in peak heart stress.
• 12mm padding also reduced peak lung strain by 38% and peak lung stress by 34%.

Conclusions:

• Alumina BPPs offer enhanced protection against BABT compared to Kevlar and UHMWPE.
• Increasing padding thickness, particularly to 12mm, is effective in mitigating biomechanical impacts on the heart and lungs.
• Material selection and padding optimization are critical for minimizing BABT and protecting vital organs in body armor design.