Deformation and failure modes of adhesively bonded elastic layers

Abstract

Adhesively bonded elastic layers with thicknesses that are small relative to their lateral dimensions are used in a wide variety of applications. The mechanical response of the compliant layer when a normal stress is imposed across its thickness is determined by the effects of lateral constraints, which are characterized by the ratio of the lateral dimensions of the layer to its thickness. From this degree of confinement and from the material properties of the compliant layer, we predict three distinct deformation modes: ͑1͒ edge crack propagation, ͑2͒ internal crack propagation, and ͑3͒ cavitation. The conditions conductive for each mode are presented in the form of a deformation map developed from fracture mechanics and bulk instability criteria. We use experimental data from elastic and viscoelastic materials to illustrate the predictions of this deformation map. We also discuss the evolution of the deformation to large strains, where nonlinear effects such as fibrillation and yielding dominate the failure process.

Adhesion mechanisms at soft polymer interfaces

“…G c /E represents an elastic length, related to the displacement that can be applied to the adhesive before failure occurs (Crosby et al 2000;Webber et al 2003). For real viscoelastic adhesives, the situation is more complex since at large strains, these materials are typical strongly non neo-hookean .…”

Waterborne Polyurethane−Acrylic Hybrid Nanoparticles by Miniemulsion Polymerization: Applications in Pressure-Sensitive Adhesives

“…Crosby et al 65 have previously considered the deformation and failure modes in soft adhesives in confinement. They explained how the initial deformation of an elastic adhesive layer is governed by a geometrical parameter (the confinement ratio), a bulk material parameter (the tensile elastic modulus, E), and an interfacial parameter, G c (the critical energy release rate).…”

“…If we estimate that G c = 0.1 Jm -2 , and use an experimental value of E = 10 5 Pa, we find that G c /Ea = 10. This is a relatively high value of this parameter, which corresponds on the deformation map to the regime of bulk failure through cavitation and fibrillation of the polymer 65 . In the macro-scale experiments, by comparison, the confinement ratio is must greater, but bulk failure is likewise expected, even though the value of G c /Ea is lower.…”

Flaw sensitivity of highly stretchable materials

“…Stretchable, transparent, ionic conductors (e.g., hydrogels and ionogels) enable devices of unusual functions, such as transparent loudspeakers [12], artificial skins [13], artificial axons [14,15], and electroluminescence of giant stretchability [16][17][18]. The interest in the mechanics of stretchable materials has surged [19][20][21][22][23][24][25][26][27][28][29][30][31][32].…”