Based on the microstructure of silica aerogel powder, a multi-scale model revealing the internal feature
of real material is constructed. The nanoporous structure and tensile properties of silica aerogel is simulated using
molecular dynamic (MD) model. The compression molding of silica aerogel powder is modeled using discrete element
method (DEM), and then the multiaxial compressive curve of real material is simulated. The MD simulation indicates
the fractal dimension of silica aerogel decreases as the density increases. Moreover, the DEM simulation reveals the elastic
modulus of silica aerogel powder is larger than that of silica aerogel while the compressive strength of silica aerogel
powder is lower than that of silica aerogel. The compressive strength of silica aerogel powder increases as the confining
stress increases.