An Analysis of Process Parameters in the Hydroforming of a Hemispherical Dome Made of Fiber Metal Laminate

Abstract

Even though fiber metal laminates (FMLs) were developed many years ago, existing forming approaches are not well qualified to produce intricate and small thin geometry. There are great difficulties in the deep drawing procedure, even for low forming depth. These difficulties are mainly related to the fiber layers limited elongation compared to the metals, and the process parameter selection during the deep drawing, which needs to be chosen very carefully. This research presents a numerical and experimental study on the influence of the hydroforming process parameters on FML hemispherical dome. The Aluminum 2024-T3 and prepreg glass fiber were used to produce the FML blanks. The parameters covered in this investigation were cavity pressure (CP), blank holder force (BHF), die entrance radius (DR), blank holder gap (BHG), and punch speed (PS). Taguchi’s design of experiments determined the effects of the input parameters on wrinkling and thinning. Results indicated that the BHG has the most significant impact on thinning and wrinkling. Optimization was conducted, and the optimum selected process parameter values were 80 kN for BHF, 15 MPa for CP, 8 mm for DR, 1.1 mm for BHG, and 30 mm/min for PS. Results revealed that FML cups formed by the optimized parameters could improve the utilization of the FMLs in mass production.