Computation of Effective Stiffness Properties for Textile-Reinforced Composites Using X-FEM

The macroscopic material behaviour of novel textile-reinforced composites is defined by its constituents (micro-level) and the design of the textile reinforcement (meso-level). Consequently, a multi-scale approach to the prediction of the material behaviour is necessary because only in this vein the adaptability of the textile reinforcement can be used to develop materials whose features can be adjusted precisely to certain applications. Due to the difference in size between the macroscopic component and the fine-scale material structure a direct modelling of the reinforcement in a structural analysis is not reasonable. Therefore, a decoupled computational homogenization procedure is applied. Based on a representative volume element (RVE) of the reinforcing architecture effective material properties (C) over bar (ijkl) for a macroscopically homogeneous continuum are computed. These properties are used to characterize the effective linear elastic material behaviour of the composite in a structural analysis and allow for efficient component analysis and design. In the process of generating numerical models for RVE of textile-reinforced composites the extended finite element method (X-FEM) is applied and an automated modelling procedure is developed. The computed effective stiffness values are compared to experimental data from ultrasonic and standard tensile tests.