9634632 Hutchinson This project is to study the micromechanics of interface adhesion and toughness with applications to thin films and multilayers. At the most fundamental level, the aim is to link interface separation at the microscopic level, the aim is to link interface separation at the microscopic level through the plastic zone to connect with macroscopic measures of interface toughness. The total work of fracture has been shown by experiments to be many times the atomic or molecular work of fracture. It is not uncommon for the plastic work of fracture to be all but a few percent of the total work of fracture of an interface. Amount the challenges addressed by the work are crack tip behavior at small scales linking to the fracture process. large scale yielding effects in films and layers, and mixed mode loadings. There is an increasing body of experimental evidence indicating that strain gradients at the micron to sub-micron level produce local hardening which exceeds that predicted by conventional plasticity formulations.
