Using microprojectiles to study the ballistic limit of polymer thin films

Area of Science:

• Materials Science
• Mechanical Engineering
• Polymer Physics

Background:

• Dynamic impact events necessitate understanding the mechanical behavior of lightweight materials under high strain rates.
• Characterizing polymers at dynamic loading conditions is crucial for applications in impact mitigation and protective systems.
• Existing methods may not be suitable for high-throughput characterization of small sample masses.

Purpose of the Study:

• To investigate the ballistic limit and dynamic mechanical properties of polycarbonate thin films.
• To establish an analytical model for energy dissipation during particle-material impact.
• To demonstrate a novel method for high-throughput dynamic mechanical characterization using minimal sample mass.

Main Methods:

• Utilized a laser-induced projectile impact test (LIPIT) to subject polycarbonate thin films to controlled dynamic impacts.
• Conducted tests at impact velocities ranging from 40 m/s to 70 m/s.
• Developed an analytical expression to model energy dissipation mechanisms and estimate material properties.

Main Results:

• Determined the ballistic limit (V0) for polycarbonate thin films within the tested velocity range.
• Successfully estimated yield stress and elasticity of the polymer using the developed analytical model.
• Demonstrated the feasibility of LIPIT for dynamic characterization of low-mass materials.

Conclusions:

• Laser-induced projectile impact test (LIPIT) is an effective technique for characterizing dynamic mechanical properties of lightweight polymers.
• The developed analytical approach allows for accurate estimation of material parameters from impact tests.
• This method offers a promising avenue for rapid discovery and characterization of advanced materials for impact mitigation.