Geometric Modeling of 3D Woven Composite Tube RVE with Cross-section Variations

When exploring the mechanical behavior of 3D woven composite under multi-axial loading, a tube sample is a feasible and easily accessible option for testing. And the investigation of performance of 3D woven composite tube under tension and torsion with finite-element method (FEM) as a tool requires a fundamental geometric model. With the idealizations of that warp is nearly rectangular and weft is nearly lenticular expressed with cubic functions, a 3D woven composite tube RVE geometric model is presented in this paper which is featured with the various cross-section shape along the yarn path. This model also takes the vertical misalignment of weft yarn stacks and flatten weft cross-sections in the surface into account. Comparing to the architecture in a real sample with each two slices from the tube circumferential and axial direction view, the largest prediction error is 6.80% while the least is 0.66% in terms of RVE dimensions, and the predicted area, width and height average error is 5.21%, 7.89% and 9.11%, respectively, validating the proposed 3D woven composite tube RVE geometric model which can be further used for mechanical behavior prediction and damage propagation.