This Is AuburnElectronic Theses and Dissertations

Modeling of Tensile Properties of Woven Fabrics and Auxetic Braided Structures by Multi-Scale Finite Element Method




Shen, Yang

Type of Degree



Polymer and Fiber Engineering


This study is undertaken to build an appropriate mechanical model for the analysis of mechanical properties of forming fabrics by incorporation of multi-scale modeling concept comprising micro-mechanical model, meso-mechanical model and macro-mechanical model. The fabric is analyzed at three different scales: yarn, unit cell and fabric sheet. The micro-mechanical model is to obtain the overall properties of yarn structure. The meso-mechanical model concentrates on the mechanical analysis of the unit cell of the fabric with the periodic boundary conditions by inputting yarns’ properties from the micro-mechanical model. The macro-mechanical model is to get the overall properties of desired fabric structure by extracting the results from meso-mechanical model. In the first part, six single-layer woven fabric samples, five two-layer fabric samples are analyzed. In the second part, a tubular braiding fabric structure made of helical auxetic yarns is manufactured and its properties are investigated by a similar multi-scale model. The models for both parts are validated by the comparison of simulation data and experimental data, which had good agreement. Detailed stress-strain field throughout the entire unit cell is determined, which can be further used in the analysis of fatigue and fracture properties.