Multiscale Simulation, Experimental Validation and Optimization of Draping-Induced Folding in Woven Fabrics

The prediction of the draping and folding behavior of textiles is important for the thermoforming of lightweight components. By assessing and controlling the fabric’s wrinkling, curved surfaces of components can be digitally optimized to ensure minimized folds and improved mechanical strength. A mechanical model for the folding behavior of woven fabrics is presented and exemplified for the shear frame test and a deep-drawing application. The presented multiscale model considers the fabric on the yarn scale, from which effective material parameters in the form of homogenized stiffness tensors are derived for a 2D sheet model on the macroscale. The experimental acquisition of the force–elongation behavior of individual rovings and the calibration of the mechanical model by comparison with shear tests are presented for four woven samples, which vary in areal density and weave type. Laser scanning is employed to attain a digital 3D scan of the displaced fabrics after deep drawing. The obtained simulation results show good agreement with physical measurements as well as the displacement fields, highlighting the practical applicability of the presented model. Another main output of the paper is a modeling-based design optimization for wrinkling reduction. We explain which parameters at the yarn and weaving level influence the wrinkles and how to modify the textile structure or yarns to reduce them.