Crack Spacing in Brittle Films on Elastic Substrates

An approximate, analytical solution is derived for the minimum spacing that can exist between a series of parallel cracks propagating in a thin film. The analysis is pertinent to the specific case of a film and substrate having identical elastic properties. In the absence of plasticity, only three parameters govern the minimum crack spacing. The cracks are predicted to be more closely spaced if the film stress or the film thickness is increased, or if the fracture toughness of the film is decreased. Copyright © 1990, Wiley Blackwell. All rights reserved