Thermal Analysis of Incoming Tape during In-Situ Consolidation by Automated Fiber Placement Using a Novel Experimental Measurement Technique and Conjugate FVM Simulation

acm7 Tracking Number 9

The temperature field of the incoming tape, particularly around the deposition region, provides important insight into the mechanisms of melting, consolidation, and crystallization during automated fiber placement (AFP) of thermoplastic composites. However, direct measurement of the internal temperature distribution within the incoming tape has remained elusive due to limitations of infrared thermography and the impracticality of conventional thermocouple placement. To address this limitation, a new experimental technology was developed to monitor the internal temperature of the incoming tape during AFP. A specially engineered sensor tape was fabricated to replicate the geometry and material of the actual thermoplastic tape while embedding a fast-response fine thermocouple at mid-thickness. The sensor tape was fed through the AFP head, enabling direct measurement of the temperature profile along its complete trajectory, from pre-heating to consolidation and subsequent cooling. This technique provides, for the first time, reliable access to temperature data within the most critical and previously unmeasurable regions of the AFP process. Complementing the experiments, a three-dimensional conjugate heat transfer model was established using the finite volume method. The model incorporates the coupled thermal interactions among the impinging hot gas flow and solid domains including incoming tape, composite laminate, and compaction roller, and employs the SST k-ω turbulence formulation to resolve detailed convective heat-transfer dynamics. Model predictions were compared with experimental results, demonstrating good agreement across the heating and cooling zones.