• Marguerès, Philippe
• Perini, L. A. Gomes
• Passieux, Jean-Charles
• Périé, Jean-Noël
• Douchin, Bernard

Abstract

Volumetric information of the microstructure of materials can be obtained by X-ray microtomography (micro-CT). In this technique, the X-ray attenuation of each material is related to their density, which determines the contrast of the resulting images. Then, materials having two or more components with closely related density may generate low contrast images. In [1], contrast enhancement techniques are used to circumvent this problem, improving the visualisation of woven composite tow architecture. Today, advances in computer chips and image processing makes the micro-CT an interesting technique to be used in experimental mechanics. For instance, determining the mechanical behavior of composite materials is a 3D problem, which calls for 3D information. When dealing with full-field measurements, the Digital Volume Correlation technique [2] allows for volumetric displacement measurements in the bulk of the material being tested. In this work, we aim at measuring the 3D displacement field at the micro scale of a composite material by using DVC. The lack of contrast in the matrix leads to poor textures at the component scale. Then, it is proposed to include a contrast agent in the matrix. At the micro scale, determining the displacement field is a problem composed of a high number of degrees of freedom. A recent DVC algorithm, based on the proper generalized decomposition (PGD), is consequently introduced.

Topics

• density
• impedance spectroscopy
• microstructure
• composite
• texture
• decomposition
• woven