Applications of Digital Element Approach in Textile Mechanics and Textile Composite Mechanics

The digital element approach (DEA) was originally developed to determine the geometry of textile composite preforms. With DEA, a fabric is considered as an assembly of unit cells; a unit cell as an assembly of yarns; and a yarn as an assembly of digital filaments. Each digital filament is discretized into a chain of digital elements. Contact force between digital filaments is calculated based on distance between them. During the past ten years, software, DFMA, has been developed based on DEA to simulate fabric deformation under external force in several areas of textile composite mechanics: determination of fabric microgeometry, simulation of fabric deformation in composite manufacturing processes, such as draping, forming and molding, and generation of conformal FEM meshes for composites with complex shapes. In this paper, principles of DEA are examined first. Applications of DFMA in the following four areas are then reviewed: 1) determine geometries of textile composite preforms with complex shapes, 2) generate conformal FE meshes for textile composites, 3) determine strength and shear characteristics of textile composite preforms and 4) simulate draping, forming and molding processes of textile composite preforms. Multiple examples are presented in detail to illustrate applications from each of the above four areas.