Analysis of Mechanical Behavior of Short-Fiber Composite using Micromechanics. 1st Report. Prediction of Stiffiness of Injection Molded Plate.

Abstract

An analytical model to relate the microstructure of an injection-molded short-fiber composite to the overall stiffness of the composite is developed. An injection-molded short-fiber composite generally has a three-layer structure ; namely, the fiber orientation distribution in both surface layers is different from that in the middle layer. First, the mechanical properties of each layer are predicted using Eshelby's equivalent inclusion method. Second, the overall stiffness of the injectionmolded composite is estimated using a laminated plate theory. Good agreement between the theoretical results based on the present model and the experimental ones in an E-glass/polyester composite is obtained. Additionally, the effects of the fiber-aspect ratio, thickness ratio of surface-to-middle layers, cut-off angle for fiber misorientation, and two- and three-dimensional distribution types are investigated by parametric study.