Dr.-Ing.

Janssen, Henning

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  • Publication
    Non-uniform crystallinity and temperature distribution during adjacent laser-assisted tape winding process of carbon/PA12 pipes
    ( 2020)
    Amin Hosseini, Seyed Mohammad
    ;
    Schäkel, Martin
    ;
    Baran, Ismet
    ;
    Janssen, Henning
    ;
    Drongelen, Martin van
    ;
    Akkerman, Remko
    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.
  • Publication
    A new global kinematic-optical-thermal process model for laser-assisted tape winding with an application to helical-wound pressure vessel
    ( 2020)
    Amin Hosseini, Seyed Mohammad
    ;
    Schäkel, Martin
    ;
    Baran, Ismet
    ;
    Janssen, Henning
    ;
    Drongelen, Martin van
    ;
    Akkerman, Remko
    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.
  • Publication
    Temperature variation during continuous laser-assisted adjacent hoop winding of type-IV pressure vessels: An experimental analysis
    ( 2020)
    Zaami, Amin
    ;
    Schäkel, Martin
    ;
    Baran, Ismet
    ;
    Bor, Ton C.
    ;
    Janssen, Henning
    ;
    Akkerman, Remko
    Laser-assisted tape winding is an automated process to produce tubular or tube-like continuous fiber-reinforced polymer composites by winding a tape around a mandrel or liner. Placing additional layers on a previously heated substrate and variation in material and process parameters causes a variation in the bonding temperature of fiber-reinforced thermoplastic tapes which need to be understood and described well in order to have a reliable manufacturing process. In order to quantify the variation in this critical bonding temperature, a comprehensive temperature analysis of an adjacent hoop winding process of type-IV pressure vessels is performed. A total of five tanks are manufactured in which three glass/HDPE tapes are placed on an HDPE liner. The tape and substrate temperatures, roller force and tape feeding velocity are measured. The coefficient of variation for each round is characterized for the first time. According to the statistical analysis, the coefficient of variation in substrate temperature is found to be approximately 4.88.8% which is larger than the coefficient of variation of the tape temperature which is 2.17.8%. The coefficient of variations of the substrate temperatures in the third round decrease as compared with the coefficient of variations in the second round mainly due to the change in gap/overlap behavior of the deposited tapes. Fourier and thermographic analysis evince that the geometrical disturbances such as unroundness and eccentricity have a direct effect on the temperature variation. In addition to the temperature feedback control, a real-time object detection technique with deep learning algorithms can be used to mitigate the unwanted temperature variation and to have a more reliable thermal history.
  • Publication
    Temperature analysis for the laser-assisted tape winding process of multi-layered composite pipes
    ( 2019)
    Schäkel, Martin
    ;
    Hosseini, S.M. Amin
    ;
    Janssen, Henning
    ;
    Baran, Ismet
    ;
    Brecher, Christian
    Tubular structures of fiber-reinforced polymer composites are utilized in various applications such as risers in the oil and gas industry and hydrogen pressure vessels in the automotive sector. The laser-assisted tape winding process presents an automated and efficient solution for the manufacturing of these structures out of thermoplastic composites. However, in order to guarantee reliable and high-quality process results, the temperature distribution within the laminate governing the consolidation between successively wound layers has to be understood and taken into account for process design. In an experimental setup, thermocouples were embedded between the layers in multiple spots along the perimeter during the manufacturing of pipe samples with five layers wound on a pure thermoplastic liner. This enabled capturing the through-thickness temperature distribution at different transversal locations. In addition to the temperature data recorded by the thermocouples, a stationary infrared thermographic camera focused on the laser-heated area was mounted on the tape winding head. The temperature data points of both sources were contrasted to evaluate how the through-thickness temperature distribution reflects the temperature input on the surface. Furthermore, the experimentally determined temperature distribution was compared with the results of a numerical process model, drawing conclusions with regard to the modelling and control of the multi-variable process.