PREDICTION OF PROCESS-INDUCED DEFECTS BY PLY-DROPS IN THE DESIGN OPTIMIZATION OF A COMPLEX COMPOSITE LAMINATE

Abstract

The objective of this work is to characterize manufacturing process-induced warping defects due to ply drops in composite laminates to guide composite laminate design. Composite laminate optimization seeks weight efficient models, but the process can also generate complex ply geometry, which compounds the challenges of the already rigorous composite laminate manufacturing process. Increased design complexity enhances the likelihood of manufacturing process-induced defects like warping; therefore, it is important to predict such defects in the design phase to make the product more efficient yet producible and thereby avoid such defects. This work study is manufacturing process induced warpage in complex composite laminates from a three-phase design optimization process that includes composite free size conceptual design ply sizing optimization, and stacking sequence optimization. A mathematical model that could be included in optimization process could help eliminate these defects in the design phase. Consequently, an Analytical model was developed to predict warpage and was compared with experimental and finite element models. The full-size optimized laminate was fabricated, to understand the manufacturing defects for an actual composite laminate. The results obtained from the analytical model correlated with the results of experimental and finite element models. Hence, the mathematical model could be incorporated into the three phase optimization process