THE ELECTRONIC SCIENTIFIC JOURNAL "YOUNG SCIENCE OF SIBERIA"

STAND FOR TESTING MATERIALS FOR FATIGUE STRENGTH

Receipt date: 
29.01.2021
Bibliographic description of the article: 

Zheleznyak V.N. Stand for testing materials for fatigue strength [Electronic resource] / V.N. Zheleznyak, L.B. Tsvik, O.L. Malomyzhev, L.V. Martynenko // "Young science of Siberia": electron. scientific journal, 2020. no. 4.

Year: 
2020
Journal number: 
УДК: 
629.4.023.2
Article File: 
Abstract: 

The operation of railway rolling stock is accompanied by the impact of dynamic loads that are not part of it, which reaches significant values, which causes the possibility of their fatigue failure.

Ensuring the fatigue strength of parts is achieved by optimizing their shapes and selecting the appropriate materials. This process is usually associated with resource testing of finished products, and consequently increases the time and cost of implementing new designs.

The article offers a stand that will replace the resource tests of finished products with laboratory tests of samples of materials of parts.

The possibility of replacing resource tests with laboratory tests is provided by using samples of materials of a special shape, which makes it possible to obtain in the latter a stress-strain state corresponding to that which occurs in parts of rolling stock with complex geometric shapes.

The sample for assessing the strength of a material under a complex stress state is made in the form of a round plate, on opposite sides of which there are grooves, respectively, located diametrically and directed at right angles to each other. Between the surfaces of the grooves that serve as mechanical stress concentrators, a bridge of the sample material is formed, located in the Central zone of the plate. The plate rests on the base. The sample is tested when a test force is applied perpendicular to its Central area.

To test the sample, a stand is used that allows creating a load by force from a compressed spring to a given value through a lever and a spherical profile punch, and a cyclic change in the load is carried out by reducing the reaction of the spring using a system of rotating eccentrics. The rotation of the eccentrics is carried out using a gear motor with a frequency of 1 Hz.

Based on the analysis of existing structures of machines for testing materials, as well as the choice of a rational form of the sample of the tested material, a test stand for fatigue strength of materials was developed and manufactured, which allows evaluating the resource of finished products in laboratory conditions.

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