Modelling the (damage) mechanics of textile composites with the aid of micro-tomography measurements

Textile-reinforced thermoplastic composites are widely used in aerospace structures, because they offer good drapability, excellent balance of stiffness and strength, fast processing conditions and potential for fusion bonded joints. On the other hand, their mechanical behaviour, especially in the presence of damage, is complicated, due to the interlacing fibres, resin rich matrix pockets and crack containment by the fibre reinforcement architecture. The Mechanics of Materials and Structures research group at UGent develops finite element simulation tools to predict damage initiation and growth in textile composites, and makes use of embedded sensors to measure local strains and deformations in the composite. Micro-tomography measurements are particularly helpful in this regard for several reasons: 1) they provide the three-dimensional geometry of the textile reinforcement architecture, which is imported in finite element simulations for further mechanical analysis, 2) cracks can be visualized in a non-destructive manner, because embedding and polishing thermoplastic composite samples for optical microscopy, is not an easy task and can lead to an altered state of the cracks, 3) the embedded sensors can be visualized very easily, and their correct alignment and position can be verified