An analytical approach of filament bundle swinging dynamics, Part I: Modeling filament bundle by ANCF

Abstract

A filament bundle is a kind of filament assembly with less twist or nontwist. It is a viscoelastic body and has a large aspect ratio. Its large deformation during motion over a wide range is a universal phenomenon in many textile processes. The dynamic viscoelasticity of the filament bundle, gravity, and air resistance are three important factors affecting the filament bundle's dynamic behavior. Taking account of these factors, a filament bundle dynamics analysis method is proposed in a series of three papers. This paper, the first in the series, presents an approach to model the dynamics of the flexible filament bundle with viscoelasticity and to analyze its dynamic behavior under the action of gravity and air resistance. The filament bundle element (FBE) is established based on absolute nodal coordinate formulation (ANCF), in which slope vectors and global coordinates are applied. The approach presented in this paper is well suited for the analysis of large deformation motions of filament bundles. As an example, a dynamic model was established to predict the filament bundle's trace during its swinging through large displacements under the action of gravity and air resistance, taking into account the filament bundle viscosity. The nonlinear differential equations of the filament bundle system were solved using MATLAB. Furthermore, the swing traces of the filament bundle in a closed Plexiglas box with different vacuum degrees were recorded using a high-speed camera to prove the validity of the established filament bundle model based on ANCF.

A dynamic modeling approach for a high-speed winding system with twin-rotor coupling

“…All textile fiber assemblies show good air permeability due to the certain voids, 25 namely, with a certain volume fraction. 26,27 Hence, the density of the package is lower than that of polyester material and the mass of the full package is m p_total ¼ 13 kg, the corresponding volume is V p_total ¼ 0.014038 m 3 . Assuming the total winding time is 1.5 hours (t total ¼ 5400s).…”

An analytical approach of filament bundle swinging dynamics, Part II: identifying equivalent dynamic constitutive parameters of filament bundles

“…The cross-sectional area of the filament bundle and its linear density show nonlinear characteristics. In addition, comparing the measured yarn diameter along a single direction, 12–16 the method proposed in this paper can quickly and accurately measure the cross-sectional contour of the filament bundle with pretension.…”

“…Particularly in lower frequencies, the linear density of the filament bundle has a great influence on the viscoelastic coefficient, and it increases as the linear density increases. According to the first paper of this series, 15 the viscoelastic coefficient of the filament bundle in which the strand number in a bundle is 24 was obtained and its value is 3.708 × 10 6 Pa; the method of theoretical simulation and experimental testing illustrated the effect of viscoelasticity on yarn dynamics and the correctness of the viscoelastic coefficient.…”

“…The cross-sectional shape and area are not only the description of the filament bundle cross-sectional state, but also the fundamental parameters of the filament bundle to investigate its dynamic characteristics, such as calculating the air resistance force and deformation energy. 15…”

“…The cross-sectional shape and area are not only the description of the filament bundle cross-sectional state, but also the fundamental parameters of the filament bundle to investigate its dynamic characteristics, such as calculating the air resistance force and deformation energy. 15 The cross-sectional shape of the filament bundle is irregular due to its fiber aggregate structure and the influence of external force. The contact measurement method will lead to a change of the cross-sectional area of the filament bundle.…”