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The paper describes the experiments aimed at the extension of the method early proposed for the uniaxial fatigue monitoring to the multiaxial modes of loading. The common denominator for both methods approach is based on the possibility of computer‐aided optical analysis of extrusion/intrusion structure, called often surface deformation relief, to be used for quantitative assessment of accumulated fatigue damage and remaining life. Experimental data obtained under the different modes of loading are presented and described as well as some objectives for the future activities are outlined.

It was shown by tests conducted at the National Aviation University (Kiev, Ukraine) that fatigue damage of metal structures may be estimated by sensors with the surface relief pattern to indicate the accumulated fatigue damage. The nature of the deformation relief has been investigated by the light, scan and transmission microscopy, as well as by a new nano-interferometer, developed at the National Aviation University. Fractal analysis of the surface patterns based on box-counting method has proved the efficiency of fractal geometry application for additional quantitative description of such surface structures. The evolution of deformation relief parameters on the sensors surface is determined by the process of the sensor and construction fatigue damage accumulation.

The possibility of using specially prepared single crystals as indicators of fatigue damage is outlined. Resuits are described of an analysis of deformation patterns deveioped in the single-crystal indicator surface, under fatigue and static loading. It is shown that the density and direction of deformation bands correlate with the number of loading cycles.

620.179.1 and T. P MaslakWe present the results of our study aimed at development of a computerized optical method of evaluation of the accumulated fatigue damage. We show a possibility of predicting the residual resource of aircraft components made from clad aluminum alloys by the deformation relief of their surface near stress concentrators. For the quantitative estimation of deformation relief we use the parameters which characterize its saturation and fractal dimension.