Predicting shrinkage and warpage of fiber‐reinforced composite parts

Abstract One major problem that arises in the design of plastic parts, especially those that are fiber reinforced, is the change of shape and dimension as a result of shrinkage and warpage. These material inhomogeneities are caused by flowinduced fiber orientation, curing, poor thermal mold lay‐out, and other processing conditions. This paper presents a simulation that predicts shirnkage and warpage of 3‐D compression molded fiber reinforced composite parts. The simulation represents the structure with the 3‐noded shell elements used in mold filling simulations. The calculated results indicate that fiber orientation strongly affect the final properties, which vary with different chage locations, have a significant effect on warpage. Unsymmetric curing, caused by uneven mold temperatures, could lead to a thermal moment that could possibly help reduce warpage.