Projectile deformation on human bone and on a polyurethane simulant.

Area of Science:

• Forensic Science
• Biomechanics
• Materials Science

Background:

• Polyurethane bone simulants are frequently utilized in ballistic testing for forensic and medico-legal applications.
• Accurate simulation of bone behavior under ballistic impact is crucial for forensic investigations.

Purpose of the Study:

• To compare the deformation of projectiles impacting human bone versus polyurethane bone simulants.
• To evaluate the suitability of polyurethane simulants for medico-legal studies involving projectile deformation and trajectory analysis.

Main Methods:

• Ductile 5.5 mm spheres were propelled at a mean velocity of 279 m/s.
• Projectiles were fired at both freshly embalmed human cranial bone and polyurethane bone simulant samples.
• Projectile deformation was measured after perforation of each sample type.

Main Results:

• Projectiles exhibited greater deformation when perforating human bone compared to polyurethane simulants.
• Neither overall bone thickness nor simulant thickness significantly influenced the degree of projectile deformation.
• A positive correlation was observed between projectile deformation and the thickness of the tabula externa in human bone samples.

Conclusions:

• The findings raise concerns about the reliability of polyurethane bone simulants for medico-legal and forensic studies, particularly in reconstructing bullet deformation and trajectory.
• Current polyurethane simulants may not accurately replicate the mechanical response of human bone in ballistic scenarios.
• Further research is needed to develop more accurate bone simulants for forensic ballistics.