Vol 52, No 9 (2016)

A review of modern state and practical applications of various digital radiography systems that are intended for nondestructive testing, evaluation, and inspection of objects is presented. The mainstream trends of development are described.

Results of theoretical and experimental studies of the attenuation of torsional waves in pipes depending on the conditions of loading on viscoelastic media, pipe dimensions, and excitation frequency are presented. The results can be used for justification of pipe testing parameters such as insonification range and sensitivity when developing guided-wave techniques for pipelines of different sizes under various service conditions.

The topicality of this work is accounted for by a need to upgrade the evaluation of the quality of winding impregnation in electric machines and to raise their safety margin and reliability. Our goal is to substantiate the possibility of using the measured capacitance of the winding of an electric machine (with respect to its magnetic core) for testing the impregnation of cavities in the major insulation and assessing metrological characteristics of the proposed testing technique. Methods of electric measurements for studying the capacitance characteristics of electric-machine windings, formulae for calculating the dielectric constant of binary mixtures, and techniques for assessing the errors of indirect measurements have been used.

A practical implementation of a technique for determining the lateral size of subsurface defects by analyzing the spatial temperature derivative is described. The technique is illustrated by inspecting a graphite epoxy composite sample that contains an impact-damage defect.

Peculiarities of additive technologies are considered, and the most typical flaws are listed. The possibility of layer-by-layer nondestructive testing of parts immediately in the course of additive manufacturing is demonstrated. Based on the review of domestic and international publications, possibilities that are offered by various physical methods of nondestructive evaluation are analyzed and potential of their usage is reviewed.