The Curved Interfacial Crack Analysis between Foam and Composite Materials under Tensile Loading

摘要

The curved interfacial crack between viscoelastic foam and composite materials under tensile loading at infinity was investigated with the complex variable displacement function. Kelvin-Maxwell model was used to represent viscoelastic characteristics of foam and Laplace transform was applied to treat the viscoelastic characteristics of foam in the analysis. The problem in the curved crack under tensile loading with frictionless contact was reduced to the Hilbert problem and a closed-form asymptotic solution was derived to incorporate the effect of curvature. The stress intensity factors in the vicinity of the interfacial crack tip were predicted by considering both anisotropic and viscoelastic properties of composite materials and foam, respectively. Unlike the crack in the single materials, the stress intensity factors near the interfacial crack between dissimilar materials are moreover related to the properties of each material and have a feature of coupled fracture mode despite single mode loading due to the inherent anisotropy of materials. To simplify the analysis of interfacial crack between dissimilar materials, the analytic model was established to have the fracture modes which were coupled only between modeⅠ and mode Ⅱ. The effects of curvature and elastic properties of composite materials and foam on the stress intensity factors near the curved interfacial crack were also investigated.