Tuesday  |  Salon 11  |  05:00 PM–05:20 PM

#15522, Behavior Under Shear Loading of a Thick Cellular Structural Adhesive

This study focuses on the link between the microstructure and the mechanical behavior under shear loading of a thick cellular structural adhesive (TCSA). In this paper, X-ray tomography and image post-processing were first used to perform quantitative microstructure analysis in 3D on parallelepipedic samples. In particular, the morphometric parameters of the cells and their orientations were studied. A skin effect has been highlighted. The boundary conditions during the foaming process seems to create local density gradients and change the cells dimensions and shape. The cells were shown to be spherical in the core of the material whereas they become ellipsoids close to the upper and lower faces of the samples. Secondly, a shear test method using an Arcan set-up with aluminum substrates coupled with digital image correlation was developed to study the mechanical behavior of the material under shear loadings. The material being cellular and heterogenous in the thickness, assumptions have to be made. It was shown that the strain field was homogeneous enough to extract the properties on a homogeneous equivalent material. Test on samples with different expansion rates and densities were performed. The use of the Gibson/Ashby relation linking the shear modulus to the density squared is a first valid approximation, at this scale, to predict and describe the mechanical characteristics of thick cellular structural adhesive.

Maxime Wetta   Université de Bordeaux
Jean-Benoit Kopp   Université de Bordeaux
Louise Le Barbenchon   Université de Bordeaux
Philippe Viot   Université de Bordeaux