期刊名称：Eastern-European Journal of Enterprise Technologies
印刷版ISSN：1729-3774
电子版ISSN：1729-4061
出版年度：2020
卷号：2
期号：7
页码：26-32
DOI：10.15587/1729-4061.2020.198451
语种：English
出版社：PC Technology Center
摘要：Existing experimental studies of the sensitivity of damping characteristics to the presence of cracks in structural elements are contradictory. Some studies declare high damping sensitivity but others conclude that a change in the dissipative ability of the structure is not enough for reliable crack diagnostics. This difference may be brought about by the influence of many factors on damping efficiency in relation to crack detection. To predict a possible change in the damping characteristic taking into consideration these factors, an experimental-analytical procedure based on the approaches of fracture mechanics was developed. This procedure has made it possible to identify conditions for reliable detection of an edge crack in a rod on two supports under transverse and longitudinal vibrations. It has been shown that the sensitivity of the damping characteristic to the presence of damage is inversely proportional to the damping level of an undamaged structure. Damping change is effective for diagnosing damages in relatively rigid structures. In this case, the stress level in the damaged area must be high enough so that the crack periodically opens or is constantly open. Based on the analysis of the study results, a condition was formulated that can help engineers easily determine the effectiveness of the damping characteristic for crack diagnostics. The damping characteristic is effective if the ratio of the energy dissipated in the crack to the two-fold potential energy of the structure deformation exceeds the product of the vibration damping characteristic of an undamaged structure by the relative error in its determination.
关键词：logarithmic decrement of vibrations;rod on two supports;edge crack;vibration-based diagnostics of damage.
