Delamination of compressed films on curved substrates

Delamination is considered for thin elastic films that are bonded to cylindrical substrates and subject to an equi-biaxial compressive pre-stress, Results for both positive and negative curvatures are obtained. The film buckles or deflects (depending on the sign of the curvature) away from the substrate inducing mixed mode stress intensities at the edge of the delamination. The energy release rate and combination of modal stress intensities at the delamination edges are determined. Steady-state propagation of delamination blisters is analyzed for both axial and circumferential propagation directions. The results depend strongly on the substrate curvature. Circumferential propagation is suppressed when the curvature is negative, but is favored when the curvature is positive. Axial propagation can occur for both positive and negative curvature substrates. (C) 2001 Elsevier Science Ltd. All rights reserved.