Laser-assisted tape winding (LATW) is a highly automated process for manufacturing tubular-like fiber-reinforced thermoplastic composites such as flywheels and pipes. One of the crucial parameters in the LATW process is the temperature of the nip point at which the incoming prepreg tape is bonded with the substrate by a compaction roller. Therefore, the temperature evolution of the nip point plays a significant role to have a proper consolidation at the tape-substrate interface. The nip point temperature is highly affected by the time-dependent geometry of the substrate and roller during continuous LATW of thick composite rings. In this paper, a critical assessment of the substrate and tape surface temperature evolution is investigated experimentally by means of a thermal camera during the LATW process of a 26-layers thick carbon/PEEK composites. A three-dimensional (3D) optical model is coupled with a thermal model in which the substrate computational domain is updated with respect to the deposited tapes. A good agreement is found between the measured and predicted tape and substrate temperatures. The total absorbed heat and heated length of the substrate and tape are described based on the roller deformation. An increase in tape and substrate nip point temperatures is found with an increase in roller deformation during consecutive winding. It is also found that the consolidation pressure and contact length at the roller-substrate interface increases during the winding process. Accordingly, the heat transfer coefficient at the roller-substrate interface is studied using the developed process model.

The non-uniform temperature and crystallinity distributions present in carbon fiber–reinforced PA12 composite pipes, produced via laser-assisted tape winding (LATW), are investigated in this paper. The width of the laser source is usually larger than the substrate width which causes multiple heating and cooling of some regions of the (neighboring) substrate and hence temperature and crystallinity gradients during the adjacent hoop winding. A kinematic-optical-thermal (KOT) model coupled with a non-isothermal crystallinity model is developed to capture the transient temperature and crystallinity distributions for growing substrate thickness and width. The predicted temperature trends are validated with thermocouple and thermal camera measurements. The substrate temperature varies in the width direction up to 52%. This will lead to extra polymer remelting and possible degradation. The maximum variation of the crystallinity degree across the width is found to be 270% which shows agreement with the trend of the measured crystallinity degree. It is found that a more realistic description of the melting behavior of the matrix is needed to obtain a more accurate prediction of the crystallinity distribution.

A new inverse kinematic-optical-thermal (IKOT) model is introduced to control the process temperature in laser assisted tape winding and placement processes. The optimum time-dependent laser power distribution is obtained by employing a grid of independent laser cells while keeping the temperature of substrate and tape at the target temperature. Multi-layer cylindrical hoop winding with laser grids of 1 × 1, 28 × 1, and 28 × 11 and helical winding of a pressure vessel with laser grids of 22 × 1 and 22 × 11 are considered. It is found that the optimized laser power distribution pattern remains the same during the consecutive hoop winding process while the total power reduces to compensate the heat accumulation. A more non-uniform laser power distribution is obtained for the helical winding because the substrate curvature changes drastically at the dome section of the pressure vessel. The change in the optimum total laser power is found to be almost constant for the helical winding case. Finally, the IKOT model is evaluated by analyzing the effect of the computational parameters on the optimized process temperature.

A new global kinematic-optical-thermal (KOT) model is proposed to provide a proper understanding and description of the temperature evolution during laser-assisted tape winding and placement (LATW/LATP) on any arbitrary shaped tooling geometry. Triangular facets are utilized in the kinematic model to define a generic tooling together with a user-defined fiber path and time-dependent process settings such as the tape feeding rate. The time-dependent heat flux distribution on the surfaces is calculated by the optical model and subsequently coupled to the thermal model. The numerical implementation of the developed KOT model is first verified for process simulations of the LATP on a flat tooling by comparing the temperature predictions with the available literature data. To validate the KOT model, a total of four pressure vessels are manufactured with in-line temperature measurements. The process temperature predictions are found to agree well with the measured temperature during the helical winding. The influence of the changing tooling curvature and process speed on the process temperature is found to be significant as shown by the experimental and numerical findings.