Yarn mobility in woven fabrics - a computational and experimental study

A finite element model is then developed to simulate yarn pull-out tests. To characterize inter-yarn friction, a Coulombic description that considers both static and kinetic friction, is implemented. The numerical model is able to describe both in-plane and out-of-plane yarn pull-out. The model is validated and used to identify mechanisms that restrain yarn mobility during yarn pull-out and how pre-tension affects this mobility. The local fluctuations in the experimental force-displacement curves are captured by the simulation, and are found to be caused by periodic alteration of the original crimped yarn profile during pull-out. Simulation results also show that most of the energy is dissipated by friction during yarn pull-out, and that the fabric stores strain energy. Pre-tension has a significant influence on both frictional energy dissipation, and strain energy in the fabric. Strain energy is found to be more sensitive to pre-tension than frictional dissipation, indicating that excessive restraint of yarn mobility may result in premature yarn failure.