Microstructural Deformation and Failure of Highly Explosive-Filled Polymer Composites Under Dynamic Compression

Area of Science:

• Materials Science
• Computational Mechanics
• Solid Mechanics

Background:

• Polymer-bonded explosives (PBXs) are highly filled composites with ~95% particle volume fraction.
• Investigating PBXs' mechanical properties and damage is crucial for safe weapon and munition use.
• Conventional methods face challenges due to the high particle loading in PBXs.

Purpose of the Study:

• To develop a numerical model for simulating the dynamic mechanical properties and damage behavior of high-particle-fraction PBXs.
• To elucidate the influence of strain rate, interface strength, and particle volume fraction on PBX performance.
• To provide a computational tool for understanding PBX response under dynamic compression.

Main Methods:

• Developed a microstructural model using the Voronoi correction method for high particle loading.
• Employed a bilinear model for stress-strain nonlinearity and a zero-thickness cohesive zone model for damage.
• Integrated a damage-based viscoelastic model with macroscopic and microscopic damage evolution equations.

Main Results:

• The numerical model accurately captures the dynamic mechanical properties and damage behavior of PBXs.
• Results show good agreement with experimental data and other simulations.
• The study quantifies the impact of strain rate, interface strength, and particle volume fraction on peak stress, failure strain, and damage.

Conclusions:

• The proposed numerical technique effectively simulates the mechanical behavior and damage response of PBXs under dynamic compression.
• The model aids in comprehending the complex interactions within highly filled composites.
• This research contributes to the safe design and application of PBXs in munitions.