Compression and Packing Density of Fibrous Assemblies

Abstract

This paper presents a generalization of the unidimensional deformation equation based on the van Wyk theory. The derivation considers the effect of uncompressed areas between contacting fibers. Theoretical results are verified by the experimental work of Baljasov. The solution is extended to cover bidimensional deformation of an oriented fibrous assembly. The work also proves the importance of using fiber packing density as the argument in the compression equation.

A novel micromechanical model of nonlinear compression hysteresis in compliant interfaces of multibody systems

“…There are numerous mechanistic models developed based on response of the fibers at the micro-level, but none of them are suitable for studying macro-level compression behavior of felt. Stamm [5] showed that the micromechanical approaches developed by van Wyk [6], Neckář et al [7], and Komori et al [8,9] failed to match experimental results for felt compression. Furthermore, Masoudi [3] utilized a more sophisticated model proposed by Alkhagen et al [10], which was based on a constitutive relation for a fiber mass using the rate theory of flexible granular solids, but unsatisfactory results were obtained for compression of felt with various volume fractions.…”

Prediction of woven fabric properties using software protkatex

“…ProTkaTex enables 3D visualization of fabrics based on the input yarn parameters. It is used for properties, prediction on the basis of combination of mathematical modeling and experimental research [2,4,31]. The major challenge is to develop a software package that industry will use in design centers for the creation and development of new fabric structures for technical as well as clothing application.…”

“…As mentioned above, the software calculates selected properties for dobby as well as jacquard woven fabric. It is possible to predict the following properties of fabrics: relative is dependent on the yarn structure and fabric input parameters (weave, warp and weft waviness, warp and weft sett) [4,33]. In the following model (1), the main infl uence is from yarn diameter and weft and warp waviness.…”

“…(Note: alternatively, this value is called the packing ratio or volume fraction.) Evidently, the fi ber packing density value must lie in the interval from 0 to 1 [4]. Type of yarn is evaluated by technology as well as yarn structure (staple yarn, multifi lament yarn, etc.).…”

“…Software ProTkaTex distinguishes the technologies: combed, carded, and open-end. Based on experimental and theoretical research work [4,32,35], different types of yarn were analyzed (on the basis of threads cross-section evaluation, see Figures 2 and 3) and their construction parameters, and mathematical equations were prepared for yarn parameters prediction. Theoretical expressions of individual parameters of yarn (fi ber packing densities, compression of yarn in relaxing state before weaving as well as in fabric, diameter of threads) were compared with experimental parameters that followed from real cross-section of yarn and woven fabric [5][6][7].…”