Loosening Detection of a Bolted Joint Based on Monitoring Dynamic Characteristics in the Ultrasonic Frequency Region

Takanori Niikura, Naoki Hosoya, Shinji Hashimura, Itsuro Kajiwara, Francesco Giorgio-Serchi

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

In typical structures and machines, bolted joints are used for easy as-
sembly, disassembly, and maintenance. However, axial force control is critical
because a decrease in the axial force (namely, the fastening force) of bolted joints
results in fatigue fractures due to the applied vibrations on the bolted joints and
chronic degradation. This work assesses the feasibility of detecting weakly
torqued bolted joints by studying the correlation between the variation in axial
force of the bolt and the shift in the natural frequency of the protruding threaded
part of the bolt. It has been shown that the rigidity of the jointed area at the base
of the protruding thread part decreases in accordance with the decrease in the
axial force of the bolt. This is attributed to a decrease in the natural frequency of
the protruding thread part. Under these assumptions, the axial force on bolted
joints is assessed. The accuracy with which axial force can be estimated depends
on the extent of the shift in the natural frequency of the protruding thread part.
To investigate the practical usability of our method on strength classification of
bolts, we assessed the performance of loosening detection in three strength clas-
sifications (4.8, 8.8 and 10.9).
Original languageEnglish
Title of host publicationthe 18th Asia-Pacific Vibration Conference (APVC 2019)
PublisherSpringer
Publication statusPublished - 2019
Event18th Asia Pacific Vibration Conference - University of Technology Sydney, Sydney , Australia
Duration: 18 Nov 201920 Nov 2019
Conference number: 18
http://apvc2019.org/index.html

Publication series

NameAPVC Proceedings

Conference

Conference18th Asia Pacific Vibration Conference
Abbreviated titleAPVC 2019
Country/TerritoryAustralia
CitySydney
Period18/11/1920/11/19
Internet address

Keywords

  • modal analysis
  • vibration
  • experimental methods
  • STRUCTURAL FAILURE
  • Steel structure
  • high frequency vibrations

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