Production of a complex shape thermoplastic CFRP structure by T-AFP with in-situ consolidation
Topic(s) : Manufacturing
Co-authors :
Renato BEZERRA (GERMANY)Abstract :
Within the LuFo project HoTStufF, the feasibility of a new concept for large primary structures of complex shape based on thermoplastic CFRP was evaluated. A flat monolithic design was proposed for the rear pressure bulkhead of commercial aircraft. The production feasibility of one of the structural panels by means of the thermoplastic automated fiber placement (T-AFP) with in-situ consolidation of the tapes was experimentally evaluated on a subscale demonstrator featuring the main geometric details of the structure.
In order to evaluate the laminate quality depending on layup process parameters, a series of trials was defined for the layup over a flat surface as well as over a 90° corner with a radius of 10 mm. The selected thermoplastic tape was a CF/LM-PAEK UD tape. The tapes were cut to 1/4" width and processed on a C1 AFP machine (Coriolis Composites). The effect of the following parameters was investigated: layup speed, nip point temperature, number of tows and compaction force.
The samples were evaluated and compared by several testing techniques. The void content was evaluated by microscopic analysis, cristallinity by DSC and the strength of the corner parts by the ASTM D6415 test method.
A suitable processing window for obtaining an in-situ consolidated laminate was defined based on the testing results. It was observed that the the parts of complex geometry did not reach the same laminate quality as the 2D panels due to local variations in processing temperature, layup speed and compaction. Some manufacturing optimization strategies for improving the laminate quality of complex shape parts are discussed.
In order to evaluate the laminate quality depending on layup process parameters, a series of trials was defined for the layup over a flat surface as well as over a 90° corner with a radius of 10 mm. The selected thermoplastic tape was a CF/LM-PAEK UD tape. The tapes were cut to 1/4" width and processed on a C1 AFP machine (Coriolis Composites). The effect of the following parameters was investigated: layup speed, nip point temperature, number of tows and compaction force.
The samples were evaluated and compared by several testing techniques. The void content was evaluated by microscopic analysis, cristallinity by DSC and the strength of the corner parts by the ASTM D6415 test method.
A suitable processing window for obtaining an in-situ consolidated laminate was defined based on the testing results. It was observed that the the parts of complex geometry did not reach the same laminate quality as the 2D panels due to local variations in processing temperature, layup speed and compaction. Some manufacturing optimization strategies for improving the laminate quality of complex shape parts are discussed.