Multiscale fracture of cellular materials
This paper presents a review of mode I fracture toughness obtained by authors from micromechanical modeling and fracture toughness test. The multiscale approach starts from cellular parameters (relative density, cell dimensions, cell topology) using micromechanical analytical or numerical models, which could be validated by classic fracture toughness test and finally extrapolated to large structures via size effect. A 2D solid representative volume was considered for numerical simulations and the fracture toughness was determined from the fracture strength of the first strut in front of the crack. The mode I fracture toughness was determine using three different specimens (Single Edge Notch Bending, Single Edge Crack and Asymmetric Semi Circular Bending). Different Polyurethane foam densities were investigated. Finally, a good correlation between analytical, numerical and experimental fracture toughness results was obtained.