Solid Propellant (previous work)

The goal of the project was to study the complex nonlinear mechanical behavior of a solid propellant, an energetic material used in propulsion. A solid propellant is an explosive highly-filled elastomer used for its chemical behavior. Consequently, its mechanical behavior is little explored. To accurately model this behavior, it is necessary to understand the relationships between the physics and the macroscopic properties.

An experimental and numerical multi-scale approach was emphasized in this work:

  • A design of experiment allowed the formulation of 20 propellants with varying composition.
  • The microstructure of these materials was characterized by physicochemical tests.
  • Nuclear magnetic resonance tests were performed for the analysis of the segmental mobility evolution of the polymer chains as the material is strained.
  • At a macroscopic scale, dynamic mechanical analysis tests were performed. 
  • At a macroscopic scale, dynamic mechanical analysis tests were performed.
  • Finally, the isotropy of the micro-mechanisms was analyzed using multi-axially prestrained DMA tests.
  • This experimental approach was complimented by numerical studies at the microscopic and macroscopic scales.

A strong nonlinearity was observed in the material behavior and micro-mechanisms of deformation were highlighted. I performed the experiments and advised two graduate students to help with the numerical work. This study provided the basis for a subsequent dissertation to develop a constitutive model of this material.