Application of laser peen forming to bend fibre metal laminates by high dynamic loading

• The study deals with laser peen forming of fibre metal laminates.
• The convex bending is produced under the high dynamic loading.
• Fibre orientation makes the bending deformation with a strong anisotropic behavior.
• The delamination failure is observed after multiple scans of arrayed laser shocks.

Forming parts from the flat fibre-metal laminates (FMLs) is very attractive to reduce the process cycle and labor cost. In this study, laser peen forming with the adaptability to produce large complex shapes is proposed to forming FMLs. Strip samples of glass laminate aluminum reinforced epoxy with different fibre orientations are prepared for experiments. The experimental results provide that the convex bending can be produced by the scanned high dynamic loading from laser irradiations. The bending is favorable to generate in the direction perpendicular to the unidirectional orientated fibres. Increasing the scanning times of arrayed laser shocks can increase the bending deformation to reach a very small saturated radius of curvature. But the risk of delamination failure is observed at the metal/fibre interface. By employing the chemical etching, the plastic deformation in the samples is found to generate in the top and bottom aluminum layers and the upper fibre layer. The study has demonstrated that the high dynamic loading of laser peen forming is a practical pathway to produce bending deformation with the sharp radius of curvature, which would be very attractive to various industrial applications.