ADVANCED DESIGN AND LIFE PREDICTION METHODOLGY FOR POLYMERIC MATRIX COMPOSITE COMPONENTS (MSC P8045)

Advanced polymer matrix composite materials offer the potential to reduce the weight of 21st century aircraft. However, a general methodology to assess the initial and lifetime response of complex material architectures with growing damage has not been demonstrated. The goal of this research plan proposed by Materials Sciences Corporation is to develop engineering analysis software that can predict the structural integrity of composite structures during a general thermo-mechanical load event. The theoretical basis for this research is a physically-based homogenization theory which combines micromechanics and thermodynamics to determine the overall response functions of multi-phase materials of arbitrary complexity. A thermodynamically-based constitutive relation is formulated using two scalar functions: a thermodynamic potential which specifies the state of the material point; and a dissipation potential which governs the evolution. The approach for deriving the constitutive and evolution equations is computationally efficient and can be easily integrated with commercial finite element codes such as ABAQUS. Tests, which include time and temperature dependence and load-unload cycles, will be conducted on carbon fiber polymide materials manufactured by Renegade Materials Corporation to provide initial model validation data. BENEFIT: Results of the proposed research will include: 1) demonstration of a physically-based modeling approach for deriving the constitutive equations for inelastic composite materials with evolving damage; and, 2) software necessary to implement the material models in commercial structural analysis packages.