Effect of hydroforming process on the formability of fiber metal laminates using semi-cured preparation

In this study, the cup part of fiber metal laminates (FMLs) was formed by a method which combines the semi-cured preparation and hydroforming processes. The FMLs in this research were produced by using glass woven fiber prepreg and aluminum 2024-T3. The process parameters were designed by Taguchi method, and the optimized parameters (3 mm pre-bulging height, 15 MPa cavity pressure, 4 MPa pre-bulging pressure and 1.15 mm clearance between blank holder and die) were obtained by range analysis. The part without defect can be obtained using the optimized parameters. The thinning rate of each layer, stress-strain distribution, and the failure modes were analyzed with experiments and numerical simulations. The results show that the middle layer has a great influence on the thinning, stress-strain distribution, and fracture modes in different directions. Numerical simulation can be used for predicting the thinning rate and fracture location. Small-size FML parts can be fabricated directly using the semi-cured hydroforming process, which can improve the production efficiency and expand applications of FMLs.