Parametric Finite Element Modeling of Cold Roll-Beating Forming of Explosively Bonded Fe/Al Layered Composites Incorporating an Equivalent Bonding Layer

A parametric finite element (FE) framework incorporating a finite-thickness equivalent bonding layer is developed for cold roll-beating of explosively bonded Fe/Al layered composites. The equivalent layer thickness is identified from interfacial characterization and the through-thickness microhardness gradient, while its quasi-static and strain-rate-dependent response is determined from nanoindentation, compression, split Hopkinson pressure bar tests, and inverse FE identification. The resulting properties are assigned to a three-layer FE model comprising the steel clad, equivalent bonding layer, and aluminum substrate. Experimental validation gives mean absolute relative errors of 8.35% and 6.20% for forming-force prediction in the spindle-speed and feed-speed series, respectively, and a mean profile normalized root-mean-square error (NRMSE) of 3.27% across six validation conditions. These errors are consistently lower than those of the simplified bilayer model. With increasing spindle speed, the peak forming force first increases slightly and then decreases, while the tooth root deepens and material pile-up increases. Increasing feed speed from 100 to 225 mm/min raises the predicted peak forming force from 13.62 to 14.98 kN but produces a shallower profile. These different trends indicate that peak force reflects local deformation resistance, whereas the final profile is governed mainly by plastic deformation accumulated over successive engagements.