Fracture Toughness of Brittle Foams

摘要

Abstract-Existing models for the fracture toughness of brittle cellular materialshave two limitations: the crack is assumed to be large relative to the cell size and the modulus of rupture of the cell wall material is assumed to be constant. In the previous companion paper, we reanalyzed the fracture toughness using a finite element analysis for short cracks and assuming that the modulus of rupture of the cell wall material followed a Weibull distribution. The finite element analysis gave a reduction factor for the effective fracture toughness for short cracks which was independent of the cell geometry. The Weibull analysis showed that the effect of cell size on the fracture toughness of brittle honeycombs is dependent upon the Weibull modulus of the cell wall material. We now apply similar ideas to the analysis of the fracture toughness of brittle foams.