Multi-Scale Modelling and Simulation of Textile Reinforced Materials

Novel textile reinforced composites provide an extremely high adaptability and allow for the development of materials whose features can be adjusted precisely to certain applications. A successful structural and material design process requires an integrated simulation of the material behaviour, the estimation of the effective properties which need to be assigned to the macroscopic model and the resulting features of the component.

In this context two efficient modelling strategies - the Binary Model [

1

] and the Extended Finite Element Method (X-FEM) [

2

] - are used to model materials which exhibit a complex structure on the meso-scale. For these investigations the focus is set on composites made of glass fibers, thermoset or thermoplastic matrices and on the application of commingled thermoplastic and glass fibers. Homogenization techniques are applied to compute effective macroscopic stiffness parameters. Problems arising from a complex textile reinforcement architecture, e.g. bi- or multiaxial weft-knit, woven and braided fabrics, in combination with a high fiber volume fraction will be addressed and appropriate solutions are proposed. The obtained results are verified by experimental test data.

The macroscopic stress and strain fields in a component are used for optimisation of the construction and the material layout. These distributions are computed in a global structural finite element analysis. Based on the global fiber orientation the required macroscopic material properties obtained from homogenization on the meso-scale are mapped to the model of the structural part. The configuration of the fiber-orientation and textile shear deformation in complex structural components caused by the manufacturing process is determined by a three-dimensional optical measurement system.