3D woven composites are becoming increasingly popular for high-performance structural applications as they offer high production rates and increased through-thickness performance [1],[2]. The ability to create novel textile structures with tailored fibre paths in a near-net-shape preform makes them an optimal solution for many applications. However, the complexity of their internal textile architecture creates significant challenges for design and performance analysis. For traditional numerical modelling techniques this constitutes a significant challenge as the material can lose its periodicity and hence the material behaviour can no longer be assumed constant across the structure. For complex 3-D textiles preforms, this issue is magnified as non-periodicity is woven directly into the textile architecture. A new modelling approach has been developed which is capable of predicting the mechanical performance of the 3D woven composites on the structural scale taking into account the internal deformations present at lower scales. This has been achieved through the creation of the software suite, SimTex. This software builds and carries out a manufacturing simulation of a bifurcated orthogonal textile, then generates feature-scale FE models using underlying textile properties for rapid and accurate structural analysis of the textile part.