Gas permeation and creep deformation of a commercial prepreg were investigated as a function of time, temperature, and consolidation pressure, identifying the viscoelastic characteristic of prepregs. Experiments using a prepreg stack demonstrated that...
Gas permeation and creep deformation of a commercial prepreg were investigated as a function of time, temperature, and consolidation pressure, identifying the viscoelastic characteristic of prepregs. Experiments using a prepreg stack demonstrated that the material exhibited a linear viscoelastic bulk deformation under vacuum/autoclave pressure and the in-plane gas flow exhibited non-Darcian flow behavior with a permeation hysteresis. This behavior was viewed and analyzed by two viscoelastic relaxation processes : (1) bulk dimensional relaxation, and (2) microscopic pore structure rearrangement. A modified standard linear solid (SLS) viscoelastic model was used to interpret the creep compliance and dynamic gas permeability utilizing two independent relaxation parameters.