A mechanical model for the prediction of the elastic properties of polymeric resins reinforced with liquid crystal polymers

The mechanical behavior of semicrystalline polymeric resins reinforced with short fiber liquid crystal polymers (LCP) under mechanical loading has bee n investigated. A micromechanical approach is considered and a representati ve unit cell model is developed and employed in conjunction with the finite element method of analysis to predict the effective elastic properties of the composite. The advantage of such an approach is that it could contain a n improved reference to the microstructural elements by including their geo metric description and their non-isotropic behavior. In the present work, t he composite is assumed to be macroscopically homogeneous and linearly elas tic with periodic fiber distribution array. The finite element method was u sed in the solution of the micromechanical boundary value problem. Three-di mensional models of the representative unit cell were generated. Models wit h varying short fiber geometry and volume fractions were developed and a nu mber of boundary conditions and loading cases were used in the analysis. Di splacement and stress fields in the composite are obtained and used in the calculation of the effective composite properties. Polypropylene composites reinforced with short fiber Vectra LCP in various volume fractions were fa bricated. Tensile experiments were performed. The model predicted effective properties are in good agreement with micromechanical equations values and experimental results.