State-of-the-art understanding of cracking for porous materials?

It seems there are quite a few experimental studies [1,2] on the fracture properties of porous materials, like nanoporous low-k dielectrics, as a function of porosity. Can anyone point out some references on the theoretical part, like the available models, computational methods or analytical approaches that can capture microstructure information, including porosity, pore geometry etc. Interface delamination of porous materials is also of interest. Thanks.

1.Wagh, A. S., J. P. Singh, et al. (1993). "Dependence of Ceramic Fracture Properties on Porosity." Journal of Materials Science 28(13): 3589-3593.
 
2.Guyer, E. P., M. Patz, et al. (2006). "Fracture of nanoporous methyl silsesquioxane thin-film glasses." Journal of Materials Research 21(4): 882-894.