Micromechanical Tensile Model of Woven Fabric and Parameter Optimization for Fit with KES Data

Abstract

Nonlinear tensile behavior of woven fabric is simulated using a simplified model of the basic cell in which tensile and bending resistances of the yarn are geometrically discretized. Geometry of the basic cell, which undergoes changes in the deformation process, is represented by the slope of the yarn. Geometric nonlinearity is accounted for by writing static equations in current configuration, and the corresponding nonlinear set of equations is solved incrementally. In order to compare the computed tensile curve with the one experimentally recorded in KES procedure of textile evaluation, residual deformation in unloading needs to be accounted for. This is done by introducing elastoplastic tensile response of the yarn into the nonlinear micromechanical model. In that way, the model covers both geometric and material nonlinearities in fabric deformation with a limited set of basic parameters. In order to refine the initial estimate of the parameters and make up for neglected secondary phenomena, the set of model parameters is optimized for best fit of computed and recorded tensile curves. The optimization is done using genetic algorithm. Very good accuracy is obtained, which seems promising for future engineering of woven fabrics.