Three-scale modeling and numerical simulations of fabric materials.

摘要

Based on the underlying structure of fabric materials, a three-scale model is constructed to describe the mechanical behavior of fabric materials. The current model assumes that fabric materials take on an overall behavior of anisotropic membranes, so membrane scale is taken as the macroscopic or continuum scale of the model. Following the membrane scale, yarn scale is introduced, in which yarns and their weaving structure are accounted for explicitly and the yarns are modeled as extensible elasticae. A unit cell consisting of two overlapping yarns is used to formulate the weaving patterns of yarns, which governs the constitutive nonlinear behavior of fabric materials. The third scale, named fibril scale, zooms to the fibrils inside a yarn and incorporates its material properties. Via a coupling process between these three scales, the overall behavior and performance of the complex fabric products become predictable by knowing the material properties of a single fibril and the weaving structure of the fabrics. In addition, potential damage during deformation is also captured in the current model through tracking the deformation of yarns in fibril scale.;Keywords: fabric; multiscale; damage; impact; modeling; armor; ballistic;Based on the multi-scale model, both static and dynamic simulations were implemented. Comparison between the static simulations and experiment demonstrates the model abilities as desired. Through the dynamic simulations, parameter research was conducted and indicates the ballistic performance and mechanical behavior of the fabric materials are determined by a combination of various factors and conditions rather than the material properties alone. Factors such as boundary conditions, material orientation and projectile shapes etc. affect the damage patterns and energy absorption of the fabric.