Wrinkling And Buckle-delamination Of Thin Films On Compliant Substrates

Compressing a thin elastic film attached to a thick compliant substrate can lead tobuckling instability and delamination, thus causing failure of the structure. Twocommonly observed modes, buckling and buckle-delamination, have each been analyzedseparately in previous studies. Recent experiments have observed that the two modes canco-exist and co-evolve. In this paper, by analytical and finite element methods, we presenta study on concomitant buckling and buckle-delamination for an elastic film on a highlycompliant substrate.Without delamination, we present an analytical solution for buckling that takes intoaccount the effect of Poisson’s ratio and size of the substrate. By using differentsuper-elastic constitutive model, we investigated the buckling wavelength and amplitudewhen the load increases. Then, we discussed the relationship between the surfacetopography and trigonometric functions, and the differences between them werequantitatively analyzed.Considering delamination, we introduced cohesive zone model (CZM) to simulate thedelamination between the substrate and the film, and the buckling induced delaminationwas studied. In this part, some factors which affect on interfacial debonding areconsidered, such as interface stiffness, ultimate strength of the interface, the energy releaserate, then an approximate formula is derived to predict initiation of buckle-induceddelamination. Compared with the trigonometric function，the effect of delamination onbuckling morphologies of the films were discussed.