Transient thermal analysis of laser-assisted thermoplastic tape placement at high process speeds by use of analytical solutions

Abstract

This article presents a transient thermal analysis of laser-assisted thermoplastic tape placement at high process speeds. The article revises modeling simplifications made in the literature and introduces novel ones. Analytical solutions to the thermal problem are proposed, for the heating and the cooling period. The process analysis of high speeds assumes a high-power laser in combination with a well-functioning temperature control. Due to this assumption, the final (surface) temperature is kept equal in all analyzed cases. The process analysis will show that the through-thickness temperature distribution changes significantly at higher speeds and becomes the determining factor for the bond interface temperature. General conclusions about process design and limits of tape placement are drawn. Finally, novel control methods are presented, which promote a dual control of surface temperature and temperature distribution. It will be shown how this is achieved by appropriate setting of the laser power and heating length.

Processing of thermoplastic matrix composites through automated fiber placement and tape laying methods

“…Kim et al 64 used a 2-D steady-state model, however, suggested that a detailed analysis considering a 3-D model is necessary due to the nonuniform hot gas impingement condition. Weiler et al 71 presented a 1-D transient model of a laser-assisted winding process and considered heat accumulation (heat reaching the back of tape or substrate) as a key phenomenon for the process, suggesting this effect needs further analysis and investigation. More 1-D transient models were reported 36,37,43,71,82,110,143 as well as 1-D steady-state gas impingement models.…”

“…Weiler et al 71 presented a 1-D transient model of a laser-assisted winding process and considered heat accumulation (heat reaching the back of tape or substrate) as a key phenomenon for the process, suggesting this effect needs further analysis and investigation. More 1-D transient models were reported 36,37,43,71,82,110,143 as well as 1-D steady-state gas impingement models. 30,31,138,148 It is obvious that most of the simulation works are based on 2-D and 1-D models with major assumptions being adopted.…”

“…122 This thermal resistance quickly decreases with increasing degree of intimate contact. 71 Thermal contact resistances were investigated in several works. 35,48,64,71,99,100,178 On the other hand, a perfect contact was assumed due to the very smooth surface of the tape and the considerably high compaction pressure.…”

“…10 A closely related process, derived from filament winding, is the tape winding process, which has a low-cost setup without a robotic or gantry-mounted head, and involves a mandrel/tool having a cylindrical shape so that circular rings can be processed. Both flat laminates 9,10,13,16,17,19,21,22,25,30,31,33,35 –69 and circular rings 20,55,70,71 –84 were investigated as well as elliptical rings. 76 Although a promising technique, ATP process still has many challenges to be overcome before it can be ful...…”

On the temperature evolution during continuous laser-assisted tape winding of multiple C/PEEK layers: The effect of roller deformation

“…The measured temperature was compared with the opticalthermal model predictions. An analytical thermal model was developed in [40] for a LATP process. It was found that the through-thickness temperature was significantly affected by the high process speed.…”