Figure 3: Modelling analysis of a yarn segment.
From: Mathematical Modeling of Yarn Dynamics in a Generalized Twisting System

(a) A yarn segment in the moving coordinate system. (b) Forces acting on a yarn element. (c) Analysis on yarn motion.
From: Mathematical Modeling of Yarn Dynamics in a Generalized Twisting System
(a) A yarn segment in the moving coordinate system. (b) Forces acting on a yarn element. (c) Analysis on yarn motion.