Modal impact testing for estimating bolted joint tightness

M. Brøns, J. J. Thomsen, A. Fidlin, D. Tcherniak, S. M. Sah

Research output: Chapter in Book/Report/Conference proceedingArticle in proceedingsResearchpeer-review

Abstract

The tension level in a bolt is difficult to determine and control. Based on simple hammer impacts, a novel technique is proposed to quantify the level of bolt tightness by analyzing natural frequencies and damping ratios of the bolt. The technique is investigated experimentally by testing two different bolts (short and long) and measuring accelerations in the transverse directions. At low tension the squared natural frequency of the first bending mode increases strongly with tension. As the bolt is gradually tightened, the squared frequency starts changing more weakly and approximately linearly with tension. By signal processing the transient response from the hammer impact, and treating problems of beat-frequencies due to the near cross sectional symmetry in the bolt, the corresponding effective linear damping ratios can also be obtained. Further, a scanning laser Doppler vibrometer (SLDV) is used to measure the mode shapes of the long bolt and it is studied how these change with tension.
Original languageEnglish
Title of host publicationProceedings of the International Conference on Noise and Vibration Engineering (ISMA2018)
PublisherKatholieke Universiteit Leuven
Publication date2018
Pages1769-1776
ISBN (Electronic) 9789073802995
Publication statusPublished - 2018
Event28th International Conference on Noise and Vibration Engineering (ISMA 2018) - Leuven, Belgium
Duration: 17 Sep 201819 Sep 2018
Conference number: 28

Conference

Conference28th International Conference on Noise and Vibration Engineering (ISMA 2018)
Number28
CountryBelgium
CityLeuven
Period17/09/201819/09/2018

Cite this

Brøns, M., Thomsen, J. J., Fidlin, A., Tcherniak, D., & Sah, S. M. (2018). Modal impact testing for estimating bolted joint tightness. In Proceedings of the International Conference on Noise and Vibration Engineering (ISMA2018) (pp. 1769-1776 ). Katholieke Universiteit Leuven.