Predicting Method of Anisotropic Elastic Constants for Injection Molded Short Glass Fiber Reinforced Composites

By studying a continuous function between the second-order tensor of fiber orientation and fiber orientation angle, fiber homogenized RVE model is established for injection molded short glass fiber reinforced composites. Based on Taguchi orthogonal test design method, the simulation of RVE model of short glass fiber reinforced composites is carried out with DIGIMAT software for quantitative analysis of fiber mass ratio(A), fiber aspect ratio(B) and fiber orientation tensor(C) on the influence of mechanical properties of short glass fiber reinforced composites. Considering injection molding process fiber layered effect, sandwich model is proposed and the lay-up design is carried out. Based on grey box theory and reverse engineering, and selecting fiber aspect ratio, surface/thickness ratio and core/thickness ratio, surface of fiber orientation tensor and fiber orientation vector rotation angle as four influence factors, the inversion to predict the orthotropic elastic constants of short glass fiber reinforced PA66(GF50) composite are carried out, and in contrast with material tensile testing elastic modulus E_(33), Poisson's ratio u_(31) and Poisson's ratio u_(32), the relative error of 0.80%, 0.29% and 1.35%, respectively.