Correlation regimes in fluctuations of fatigue 6802 , USA A crack growth

rowth of tructures k damage y strong ales. The paper, is dynamics damage iated by estimated e setting. This paper investigates correlation properties of fluctuations in fatigue crack g polycrystalline materials, such as ductile alloys, that are commonly encountered in s and machinery components of complex electromechanical systems. The model of crac measure indicates that the fluctuations of fatigue crack growth are characterized b correlation patterns within short-time scales and are uncorrelated for larger time sc two correlation regimes suggest that the 7075-T6 aluminum alloy, analyzed in this characterized by a micro-structure which is responsible for an intermittent correlated of fatigue crack growth within a certain scale. The constitutive equations of the measure are built upon the physics of fracture mechanics and are substant Karhunen–Loève decomposition of fatigue test data. Statistical orthogonality of the damage measure and the resulting estimation error are demonstrated in a Hilbert spac r 2005 Elsevier B.V. All rights reserved.