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Mechanical Testing and Numerical Simulation of Mechanical Structure-Property Relationship of Silica Aerogel

Shimpi, Nilesh
Silica aerogel are highly porous nanostructured solids materials with wide range of applications. However silica aerogels are inherently fragile and brittle. Thus, their use in load-bearing applications presents a challenge. Mechanical behavior of nanostructured silica aerogel is characterized under compression and three-point bending tests. In order to develop a better understanding of the synergistic stiffening and strengthening mechanism of the crosslinker a numerical model was developed using Particle Flow Code. The compressive strength increased 40 times the strength of plain silica aerogels. Testing was also carried out under different strain rates and temperatures. In flexural tests the stress-strain curve obtained showed a perfect elastic behavior and the "conchoidal" fracture morphology. The results from numerical modeling emphasis need for a better algorithm that can generate the silica aerogel structure. Also the quantitative parameters determined from modeling need to be experimentally validated.