1. Application of the Acoustic Emission Method to Ranking Fatigue Damage in the Material of the Trunnions of Drying Cylinders in Cardboard- and Paper-Making Machines.
- Author
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Rastegaev, I. A., Khrustalev, A. K., Danyuk, A. V., Afanas'yev, M. A., Merson, D. L., Sevast'yanov, D. V., Melent'ev, S. V., and Plyusnin, A. D.
- Subjects
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FRACTURE mechanics , *MATERIAL plasticity , *ACOUSTIC emission , *FATIGUE cracks , *CYCLIC loads , *METAL fatigue , *FRICTION - Abstract
Using the example of assessing the technical condition of the trunnions of drying cylinders in cardboard machines (CBM), the question of the possibility of ranking cyclically loaded elements of dynamic equipment according to the degree of damage to their material by fatigue cracks using acoustic emission (AE) measurements is discussed. As a result of special laboratory studies with varying loads in the cycle of loading and lubrication of crack edges, the features of AE due to the friction of crack edges and plastic deformation at the crack tip during its growth in a viscous material have been established. It is shown that during cyclic loading of the material, AE signals from the friction of its banks are detected more steadily than AE signals due to a crack jump with an increase in its length, and that tracking the former ensures the detection of fatigue damage in the material even under loading conditions insufficient for crack growth. Based on the data obtained, three AE signs of the presence of fatigue damage in the material of the elements of dynamic equipment were developed under the condition of cyclic activation of the movement of crack edges. As a result of industrial testing of the developed AE signs, their operability was confirmed, their boundary values on the operating trunnions of CBM drying cylinders were clarified, and a method for ranking trunnions by the level of damage due to fatigue cracks was proposed. By comparing the results of AE measurements with ultrasound testing, the reliability of the proposed approach was evaluated and showed the probability of detecting a fatigue crack in the trunnions of CBM drying cylinders at the level of 71%, with the probability of skipping and false rejection of the product of 12 and 17%, respectively. The developed technique is also transferable to other massive dynamic equipment after clarifying the boundary values of AE signs of fatigue damage in the material on this type of facilities. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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