Numerical modelling of 3D woven preform deformations

In order to accurately predict the performance of 3D woven composites, it is necessary that realistic textile geometry is considered, since failure typically initiates at regions of high deformation or resin pockets. This paper presents the development of a finite element model based on the multi-chain digital element technique, as applied to simulate weaving and compaction of an orthogonal 3D woven composite. The model was reduced to the scale of the unit cell facilitating high fidelity results combined with relatively fast analysis times. The results of these simulations are compared with micro computed tomography (CT) scans of a dry specimen of fabric subjected to in situ compaction. The model accurately depicted all of the key features of the fabric including yarn waviness and cross-sectional shapes as well as their development with compaction. A parametric study is presented to characterise the effect of the model inputs on the analysis speed and accuracy.