Vol 9, No 3 (2023)

The influence of the notch depth of a semicircular profile on the multi-cycle fatigue of solid and hollow cylindrical samples made of steel 20 with diameter 25 mm under outstripping surface plastic deformation was studied. It was revealed that with an increase in the notch depth from 0.3 mm to 1.0 mm, the endurance limit of notched samples decreases with the same hardening treatment. To maintain the hardening effect during multi-cycle fatigue with increasing notch depth, it is necessary to increase the thickness of the hardened surface layer of the samples with outstripping surface plastic deformation. It has been established that to assess the influence of surface hardening on the endurance limit of samples with notches of various depths, one should use the criterion of average integral residual stresses calculated from the thickness of the surface layer of the dangerous cross-section of the sample, equal to the critical depth of a non-propagating fatigue crack.

It is known that pressure pulsations have a significant impact on the performance of various power plants, including the gas turbine engine, reducing the compressor stall margin and the combustion efficiency in the combustion chamber. Engine development with account for pressure pulsations requires measuring equipment for increased pressure, temperature and vibration pulsations over a wide frequency range. In this regard, the frequency test bench created by the efforts of young engineers and graduate students of the Automatic Systems of Power Plant Department is successfully used at Samara University to check the equipment for research of pulsation processes in GTEs. A variety of acoustic probes and other dynamic measurement tools have been and are being tested on the bench. In particular, a set of frequency tests has been carried out for the engine-building enterprise, some results of which are given in this article. It should also be noted that the performance capability of the test bench is far from exhausted and, in addition, the scope of application of the test bench can be significantly expanded.

The material of the article can be useful for specialists who develop and apply measuring equipment for pressure pulsations in stress conditions, for example, at the stage of gas turbine engine development.

A cascade algorithm has been developed that allows identification of contents in production containers. The algorithm consists of two stages: detection of container cells and classification of the contents of each cell. The proposed algorithm makes it possible to achieve a classification accuracy of 89% when trained on a relatively small sample size than would be required when using a direct part detection algorithm, without the cell detection stage. The algorithm is thus suitable for use in environmental monitoring systems in aerospace manufacturing.