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

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.