Mechanical properties of milimetric silica aerogel particles produced through evaporative drying: A coupled experimental and discrete element approach

International audienceAn alternative to supercritical drying to process silica aerogels is to apply evaporative drying to obtain particles that can then be used in the preparation of composite products. However, the mechanical behaviour of these particles is still poorly understood. In this work, millimetre-sized particles are studied combining experimental testing and discrete simulations. A statistical study of the compression of individual particle shows that the values of fracture strength are scattered because of the variability in shape, density and initial defects. The individual compression of aerogel particles inside an X-ray tomograph provides valuable information for understanding the influence of density on their elastic and fracture behaviours. Discrete simulations are calibrated using experimental data to reproduce numerically experimental compression observed inside the tomograph allowing the introduction of process induced particle defects. We show that these simulations can be used to determine the Young’s modulus and fracture strength of aerogel particles