X-μCT and DVC use for composite materials analysis

The complex mechanical behaviour of composite materials, due to internal heterogeneity and multi-layered composition imposes deeper studies. This paper presents an experimental protocol to perform volume kinematic measurements in composite materials. This work is centered on the transverse shear effects in relation with the composite materials mechanical behaviour. A lot of theories exist in literature to consider the existing warping section during high transverse shear stresses, but very few studies have been realized in the experimental way. The association of X-ray micro-computed tomography acquisitions and Digital Volume Correlation (DVC) technique allows the measurement of displacements and deformations in the whole volume of composite specimen. To elaborate the latter, composite fibres and epoxy resin are associated with metallic particles to make contrast in X-μCT acquisitions. A specific in-situ loading device is presented for three-point bending tests, which enables the visualization of transverse shear effects in composite structures