Tracing the void content development and identification of its effecting parameters during in situ consolidation of thermoplastic tape material

One of the ways to identify the quality of structures made from fibre-reinforced thermoplastic material is by examining its void content percentage. Significant improvement in mechanical properties can be achieved by minimising it. The purpose of this work was to develop a simulation tool from existing available model in literature, to trace out the void development inside the laminate during the manufacturing and identification of major influencing process parameter. The effects of consolidating force, process velocity, hot gas flow in the heating region, and repetitive passes were investigated through simulation. A series of experiments was carried out on several AS4/PEEK laminated plates manufactured by automatic tape placement process. Simulated void distribution through thickness and density were compared with measured values to trace the effecting input parameters. Thickness build-up with successive lay-ups is also monitored online and the average thickness lies in close proximity to the predicted range. Major influencing process parameters were identified. © Smithers Rapra Technology, 2010.