Mechanical behaviour of aerogels and composite aerogels submitted to specific penetration tests

Abstract

Silica aerogels are potentially ideal candidates to capture fast moving particles in their ultra-porous compliant structure and aerogel capture cells have been deployed in low earth orbit on a number of occasions. It is consequently interesting to better characterize the mechanical properties of these ultra-porous materials under very large deformation and collapse. Some special flat punch indentation experiments are used in this study to test these properties. The large flat punch penetration induces the creation of a track in the sample with a series of pilled Hertzian cone cracks and samples can resist without breakage for penetration depth of several millimeters. The influences of the aerogel density and of the penetration rate are checked in both standard and fibers reinforced aerogels. The lower the density, the more compliant the aerogel is to large penetration.