Effective toughness of heterogeneous brittle materials

✍ Scribed by S. Roux; D. Vandembroucq; F. Hild

• Publisher: Elsevier Science
• Year: 2003
• Tongue: English
• Weight: 236 KB
• Volume: 22
• Category: Article
• ISSN: 0997-7538
• DOI: 10.1016/s0997-7538(03)00078-0

✦ Synopsis

A heterogeneous brittle material characterized by a random field of local toughness K c (x) can be represented by an equivalent homogeneous medium of toughness, K eff . Homogenization refers to a process of estimating K eff from the local field K c (x). An approach based on a perturbative expansion of the stress intensity factor along a rough crack front shows the occurrence of different regimes depending on the correlation length of the local toughness field in the direction of crack propagation. A "weak pinning" regime takes place for long correlation lengths, where the effective toughness is the average of the local toughness. For shorter correlation lengths, a transition to "strong pinning" occurs leading to a much higher effective toughness, and characterized by a propagation regime consisting in jumps between pinning configurations.