The ballistic performance of bone when impacted by fragments

Area of Science:

• Biomechanics
• Materials Science
• Forensic Science

Background:

• Computer simulations of explosive devices require physical models for algorithm development.
• Understanding weapon effects is crucial for designing protective equipment and structures.
• Limited research exists on bone's response to fragment impacts, unlike skin and muscle.

Purpose of the Study:

• To investigate the ballistic performance of bone when impacted by fragment simulating projectiles (FSPs).
• To characterize bone failure modes across a range of impact velocities and kinetic energy densities.
• To provide critical data for improving computational models of ballistic trauma.

Main Methods:

• Ballistic testing of isolated swine ribs using 5.5 mm ball bearing (BB) and 1.10 g chisel-nosed (CN) FSPs.
• Impact velocities ranged from 99 to 1265 m/s.
• High-speed videography, X-radiography, and micro-CT scanning were used for post-impact analysis.

Main Results:

• Bone perforation occurred at kinetic energy densities (KED) as low as 0.14 J/mm².
• Chisel-nosed FSPs transferred more energy, causing greater bone damage and secondary fragment generation.
• High-velocity impacts (>551 m/s) resulted in brittle bone failure.
• Low-velocity impacts (<323 m/s) showed a transition from elastic to plastic to brittle failure modes.

Conclusions:

• Bone exhibits complex failure behaviors dependent on impact velocity and projectile type.
• The findings provide essential data for validating and refining physical models used in ballistic simulations.
• This research enhances understanding of bone injury mechanisms in fragmentation events.