Micro-CT analysis of the internal deformed geometry of a non-crimp 3D orthogonal weave E-glass composite reinforcement

An investigation at the unit cell level of the sheared geometry of a single layer E-glass non-crimp 3D orthogonal woven reinforcement (commercialized under trademark 3WEAVE by 3Tex Inc.) is performed by X-ray micro-computed tomography (micro-CT) observations. The aim is to observe, understand and quantify the effect of in-plane shear deformation on the composite reinforcement geometry, at mesoscale (i.e. unit cell level). It was observed that, increasing the shear deformation, Z-yarns maintain unchanged the distance between the yarns and as consequence the yarn cross-section has a reduced variation of width, mainly in the weft direction. Furthermore, the effect of the shear angle on the textile thickness during compression is measured, this being an important parameter after the forming and molding phases of a composite component production. Compression tests and micro-CT measurements of the thickness show similar values and are in agreement with the prediction obtained assuming the theoretical invariance of the volume in the considered range of shear deformations.