Thermal Analysis of in-situ Thermoplastic Composite Tape Laying

Abstract

This paper presents analytical and numerical thermal analysis for melting and consolidating impregnated composite tapes in the presence of a localized heat source. This analysis also leads to the prediction of the processing window for a given tape-laying configuration. Heat of melting/solidification is included in the form of a heat generation term. A separation of variables method is employed to solve the governing equations ana lytically. In the numerical analysis, the governing equations are discretized using a non uniform mesh and are solved using a finite difference approach. The processing parame ters, such as consolidation speed, heat intensity, heat source width, etc., as well as material properties are incorporated within the analysis. The results show large thermal gradients in the vicinity of the consolidation point. The error between the analytical solu tion and the numerical result is found to be 3 % for the maximum temperature, and the maximum error for the temperature over the entire domain is observed to be 7%. The effects of processing speed, heat intensity, and the width of the local heat source are inves tigated, and the overall optimization of the process is discussed.

Design, Analysis, Manufacture, and Test of APC-2/AS4 Thermoplastic Composite Pressure Vessels for Deep Water Marine Applications

“…The larger the size of the processing window, the easier to control the processing and quality of the manufactured parts [18][19][20][21][22]. Finally, the compaction roller (shown schematically in Figure 19 and given in Figure 20) should apply enough pressure on the lay-down point to facilitate the consolidation process for the incoming composite tape on to the substrate [22][23][24][25].…”

A review of radiative heating in automated layup and its modelling

“…Therefore it is also considered in this review, reflecting studies and machinery covering both filament winding and automated layup, as classification can be difficult, especially for thermoplastic processing where a compaction roller is always required [11,28,31,53]. In fact, the first applications of laser heating technology were performed with thermoplastic filament winding, where it was selected for its highly focused energy input over infrared radiators [7,54,55]. Nonetheless, infrared heating has also been used for this process, as the stationary setup allows for extensive heating stages [13,56,57].…”

“…To account for heat transfer due to head movement, material is convected with a velocity opposite to the movement speed of the layup head through the fixed coordinate system [31]. This requires the introduction of boundary conditions for the incoming and leaving tape, which have to be defined far enough from the heated region [25,54]. The Lagrangian approach on the other hand is used to describe the temperature as a function of time, thus requiring the transient heat conduction to be solved for a coordinate system fixed to the mould [77,82,83].…”

Issues Related to Processability during the Manufacture of Thermoplastic Composites Using On-Line Consolidation Techniques

“…The temperature of the base-plate is assumed to be maintained at 140°C as well. Practically, this simulates a process in which &dquo;global&dquo; heaters maintain elevated tape and substrate/base-plate temperature and the local heat source is limited to supplying the local, incremental energy needed for the polymer melt [21]. The hot winding process appears to be most suitable for in-situ processes where a focused local heat source, such as a laser [6,18], is used to augment the temperature of the consolidation point from the control temperature to temperatures above the melting points where consolidation is possible (i.e, within the processing window).…”