Controlled, Stable Processes
The composite manufacture of aircraft parts requires an integrated, tailored process chain. The CNC functionality of the Sinumerik 840D from Siemens Industry guarantees controlled, stable processes.
Posted: April 5, 2013
The composite manufacture of aircraft parts requires an integrated, tailored process chain. The CNC functionality of this control guarantees controlled, stable processes.
The aerospace industry increasingly uses carbon fiber-based composite materials for wings, tail assemblies and fuselage segments. Tape laying and fiber placement have now become key technologies in aircraft construction.
In the case of tape laying, 70 mm to 200 mm wide tapes, made from carbon fibers and composite resin, are placed layer-by-layer on a flat support and are then cut off parallel to the edges of the workpiece. Where edges are complex, pre-cut tape segments are used, which requires the tape to be positioned very precisely.
The fiber orientation of the tape must, where possible, conform exactly to the direction of the point tension that will occur in the material during flight. For this reason, the tape must be applied without any tension or folds and with precisely defined pressure.
As a result, instead of wider tapes, components with complex curved surfaces such as the segments of the aircraft fuselage, have several very narrow tows placed on the mandrel of fiber placement machines.
To achieve the maximum strength and load capacity of the aircraft component, the tape layers must be applied to each other so that they adhere across the whole surface, without any air or dust entering. Therefore, the quality requirements for placement are uncompromisingly high.
To prove out the quality and safety, each composite component is subjected to an extensive, area-wide and nondestructive material test. If delamination is detected during this test, the entire part is normally rejected, which means a considerable amount of time and material is lost, especially on large-scale aircraft components.
The economic and timely manufacture of wings and fuselage parts made from composite materials requires the reliable control of tape laying and fiber placement quality, as well as new solutions for drilling, cutting and trimming operations.