Researcher/lecturer, University of,
Pages: 18 Published: Jan 1988
The fatigue crack-tip deformation in the 7075-T6 aluminum alloy has been studied by moiré interferometry, which is a coherent optics technique for full-field in-plane displacement measurements in the submicrometre range. For constant-amplitude-loading conditions the local strain distributions and the crack-tip plasticity have been correlated with theoretical descriptions and models. The effects of a 60% overload on crack propagation has been investigated in terms of flaw profiles and the effective stress-intensity factor. Cyclic plasticity was originally found to depend qualitatively on crack length as much as on the overload-affected growth rate. The implications on crack closure of the moiré results are also discussed.
fatigue, crack propagation, fracture mechanics, overload effects, crack closure, stress-intensity factor, material plasticity, aluminum alloy, coherent optics, moiré interferometry, nonlinear fracture mechanics
Paper ID: STP26786S