Abstract: 

High speed warp knitting represents a well-established method for textile production. Production speeds using highly elastic yarn are limited to 4400 rpm due to lapses in quality. This research project is tasked to develop a monolithic modeling approach of the warp knitting process with a focus on the yarn dynamics in the multibody environment Simpack. The dynamic modeling of conventional textile production machines in multibody systems is well understood, therefore there is a focus on approaches of yarn modeling. The modeling approach has been delineated by a series of requirements. The model must contain tensile and bending stiffness. Additionally, the reliable contact of neighboring yarns, self-contacting behavior, and reli able environmental contact (i.e. machine contact) must be accurately resolved. Due to the temporary loss of yarn tension during mesh formation, bending effects become significant and the bending stiffness must therefore be considered. The yarn has been modeled using nonlinear Simbeam bodies. Using the option to disconnect the physical cross-sectional properties from the mechanical properties, nonlinear material behavior can be approximated. Polygonal Contact Method (PCM) is used to model contact between two yarns. The square knot is selected as a benchmark model and simulated. It can be shown that this modeling approach is generally feasible. That said, it requires a high number of degrees of freedom and a high discretization, significantly increasing the state vector size and therefor the required computational effort. Staggered grid discretization employed in Simbeam bodies represents a limiting factor for this approach.

Presenters: 

Jan Schröder Researcher - Technische Universität Dresden Jan Schröder is a researcher and doctoral student at the Institute of Solid Mechanics at Dresden University of Technology. He holds a Dipl.-Ing. degree (M.Sc.) in mechanical engineering. Working with Simpack for over 5 years, he gained experience as a student research assistant, industry intern at CLAAS, researching excitation behavior of gears for his diploma thesis and since march 2025 as a fulltime researcher. He specializes in modeling yarn dynamics in high-speed warp knitting using Simpack.