https://popups.uliege.be/esaform21/index.php?id=3975 Index terms fr 0 https://popups.uliege.be/esaform21/index.php?id=2798 Anisogrid lattice cylinders have been produced by means of an innovative out-of-autoclave (OOA) process by using thermoplastic prepreg. Unidirectional thermoplastic tapes with polypropylene matrix and glass fibers were wound on cylindrical mandrels at room temperature. Composite consolidation was achieved by using the compression of a heat-shrink tube during its shape recovery in oven. A cylindrical anisogrid lattice structure was manufactured and mechanically tested under vertical loading. Results from the buckling test revealed the optimal adhesion between prepreg layers after the out-of-autoclave molding. Numerical modelling of buckling has been performed to correlate the structural behavior of the anisogrid lattice cylinder with composite material properties and geometrical features. A parametric model of the lattice structure has been defined for this aim. The proposed manufacturing technology combines the advantages of thermoplastic composites (reparability, easy handling, easy storage, long prepreg life, productivity) with the designing potential of anisogrid lattice structures in terms of lightness and stiffness. Wed, 24 Mar 2021 19:03:10 +0100 Sat, 10 Apr 2021 13:57:00 +0200 https://popups.uliege.be/esaform21/index.php?id=2798 https://popups.uliege.be/esaform21/index.php?id=4351 Fiber reinforced thermoplastic composites have shown to be attractive for industry as they can be reused, reshaped, welded and repaired, while keeping mechanical properties on par with thermoset composites. Since thermoplastics usually have high melt viscosities unsuitable for liquid composite molding processes, in-situ synthesis of PA6 from ε-caprolactam is considered. Its reactive mix has low viscosity which allows impregnation. However, the coupled crystallization and polymerization affects the resin viscosity and its flow is altered by the dual-scale permeability of the fiber preform. Thus, to predict the local differences in the thermoplastics properties, a coupled polymerization crystallization model needs to be integrated in the LCM processing simulation at representative scales. This study aims to propose a reliable simulation of the resin flow through a fibrous preform. Hence, viscosity measurements on the reactive mix are achieved using a rheometer with parallel-plate geometry, aiming to associate a viscosity model with the Hillier coupled polymerization-crystallization model previously determined by Vicard. The full chemorheological model will then be integrated into a simulation of LCM process in OpenFOAM®, an open source CFD software in order to follow the extent of the synthesis in the resin flow during the process. As a future work, simulations including microscale tow information extracted from a real textile specimen will permit to investigate the effect of permeability and double scale porosity in fibrous preforms on the final polymerization rate and crystallinity. Thu, 01 Apr 2021 21:46:38 +0200 Thu, 01 Apr 2021 21:46:38 +0200 https://popups.uliege.be/esaform21/index.php?id=4351