Open AccessAcceptable Residual Stresses Value Criteria for Rail Stress State
Author(s) -
К. А. Тапков
Publication year - 2021
Publication title -
intellektualʹnye sistemy v proizvodstve
Language(s) - English
Resource type - Journals
eISSN - 2410-9304
pISSN - 1813-7911
DOI - 10.22213/2410-9304-2021-4-26-32
Subject(s) - gost (hash function) , residual stress , finite element method , residual , multiphysics , divergence (linguistics) , structural engineering , stress (linguistics) , constant (computer programming) , component (thermodynamics) , materials science , mathematics , physics , computer science , engineering , statistics , composite material , algorithm , linguistics , philosophy , thermodynamics , programming language
According to simulating and experimental research, the negative linear relation between the level of residual stresses, assessed by the method of acoustic tensometry, and the divergence of the notch in the rail cut in accordance with clause 7.14 of GOST 51685-2013, was found. The correlation coefficient is 0.94. It was determined by the method of regression analysis that the sensitivity of inclination of the notch is the same for different rail casts with account of the measuring errors and it is minus 0.032, but the constant component of the expression is different for different casts of the rail. The constant component should be assessed according to the results of the tests of residual stresses by destructive methods (cutting the rail) in accordance with 7.14 GOST 51685-2013. After evaluating the constant component for each of the rail casts, the dependence can be obtained that describes the notch divergence depending on the level of the measured residual stresses. When the descrepancy of the notch does not exceed 2 mm, the stress state of the rail is acceptable by GOST 51685-2013; the predicted notch discrepancy of the notch is calculated according to the dependence given in the paper. Experimental evaluation of residual stresses was carried out using the EMA method of wave input-reception and the acoustoelasticity effect. Mathematical modeling was carried out by the finite element method using the Comsol Multiphysics environment. The size of the finite elements is adaptive, the size of the element ranges from 0.2 mm to 3 mm. To simulate residual stresses, distributed loads with a gradient character were applied to the rail, selected so that at a given level of stress across the rail elements, the stress transition had a smooth character.