Asymmetric Shielding in Interfacial Fracture Under In-Plane Shear

摘要: The toughness of a glass/'epoxy interface was measured over wide range mode mixes. A toughening effect associated with increasing positive and negative in-plane shear components. Optical interference measurements normal crack opening displacements near the front complementary finite element analyses were used to examine near-front behavior during initiation. Estimates tough­ening based on plastic dissipation, bulk viscoelastic asperity shielding did not fully account for values. results suggest that inelastic epoxy, frictional, and, perhaps, three-dimensional effects should be considered. 1 Introduction Interfacial growth occurs in number applications technological importance. Because fact frac­ture path is constrained irrespective orientation globally applied loads also because mismatch material properties across interface, in­herently mixed mode. Critical subcritical must then governed by some combination I, II, III fracture parameters. simplest approach, using one parameter, seeks determine an effective parameter can all mixes unifying manner. This particularly useful where corre­lations rates fall curve when proper found. An alternative consider two-parameter approach represents mix or direction other magni­tude. For critical growth, magnitude will generally function mix. form usually determined experimentally but may, as mechanisms are better understood, even predicted. most common examining interfacial initiation has been tough­ness, G