Automated manufacturing of Fibre Metal Laminates (FML)

Prototype application of an innovative manufacturing process by the example of a large fuselage part


Fibre metal laminate is a composite material consisting of alternating layers of aluminium foil and pre-impregnated glass fibre. Creation of the preform offers various challenges for an automated implementation. The aluminium foils can be several meters long with a width of 0,3 mm. Handling end-effectors and processes have to ensure safe transport without inducing damage like wrinkles or dents. A pick & place approach with two cooperating robots has been selected for this.

The glass fibre material is provided on rolls and is applied with a continuous rolling motion and on the fly cutting.

Offline programming

Based on the part design determined by the plybook all robot programs required for the lay-up can be generated automatically. A software tool selects grip and drop points for every cut-piece and derives the curvature for the end-effectors in order to emulate the tooling surface. A collision-free path to the required position can be simulated and selected.

Lay-up of aluminium and glass fibre

The end-effectors for the handling of aluminium sheets are modular and can emulate the curvature of the tooling. Application of cut-pieces both in longitudinal and circumferential direction is possible. Vacuum-based grippers can safely handle sheets up to 8 m.

Glass fibre prepreg is applied with a continuous and rolling motion. Cutting of the material is done with ultrasonic knives. Potentially the lay-up of a width of 460 mm is possible though the size is subject to local curvature.

Inline Quality Assurance (QA)

In order to increase confidence in the process and enable detection of defects in an early production stage inline quality assurance measures are applied.

Positioning of the cut-pieces is verified during the lay-up process via TScan. This laser based triangulation system generates a 3D point cloud of the surface. An algorithm identifies the edge which then can be matched to the required position given by the plybook.