Safely Secure Fasteners in Critical Applications

It can be vital that bolted joints holding subassemblies together remain secure. Fasteners used to secure bolts and screws should resist the loosening caused by vibrations and dynamic loads, while keeping the ease of removability during maintenance. When a threaded fastener is subjected to vibration, the rapid movement causes a lowering of friction against the threads and a subsequent loss of preload. The loss of preload allows the fastener to vibrate loose and could lead to catastrophic consequences for critical applications. To mitigate the problem of unintentional bolt loosening, one must understand what parameters are critical in the bolted joint that affects this. The critical displacement threshold and the Junker vibration principle will be discussed to understand these self-loosening effect and the ways to reduce the risk. There are many locking methods that are out on the market today to prevent this bolt self-loosening from occurring. While some are effective when the dynamic loads are mild, certain applications such as the aviation industry needs to have a locking method that can withstand harsh dynamic and vibratory conditions where self-loosening is not an option. The Junker vibration test will analyze these locking systems to compare among them how effective they are under extreme transverse loading conditions where bolt loosening is most susceptible. Several locking methods will be compared under this test procedure and analyzed.


  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; Photos; References;
  • Pagination: 8p
  • Monograph Title: 2014 FAA Worldwide Airport Technology Transfer Conference Proceedings: Innovations in Airport Safety and Pavement Technology

Subject/Index Terms

Filing Info

  • Accession Number: 01538276
  • Record Type: Publication
  • Report/Paper Numbers: S10016
  • Files: TRIS, ATRI, USDOT
  • Created Date: Sep 9 2014 6:30AM