Delamination of compressed films on curved substrates

Delamination is considered for thin elastic films that are bonded to cylind rical substrates and subject to an equi-biaxial compressive pre-stress, Res ults for both positive and negative curvatures are obtained. The film buckl es or deflects (depending on the sign of the curvature) away from the subst rate inducing mixed mode stress intensities at the edge of the delamination . The energy release rate and combination of modal stress intensities at th e delamination edges are determined. Steady-state propagation of delaminati on blisters is analyzed for both axial and circumferential propagation dire ctions. The results depend strongly on the substrate curvature. Circumferen tial propagation is suppressed when the curvature is negative, but is favor ed when the curvature is positive. Axial propagation can occur for both pos itive and negative curvature substrates. (C) 2001 Elsevier Science Ltd. All rights reserved.