726 Diagnosis of bolt loosening based on instantaneous frequency of ultrasonic wave transmitted through the thread

Bibliographic Information

Other Title
  • 726 ねじ山を透過した超音波の瞬時振動数に基づくボルトの緩み診断

Search this article

Abstract

Bolt loosening is one of the important issue in the industrial field. We have proposed a testing method for the bolt loosening using ultrasonic pulse which is projected to side of the bolt. The proposed method can evaluate tightening torque of stainless-steel bolt in an aluminum base block via instantaneous frequency of the ultrasonic pulse transmitted around the bolt. On the other hand, a non-invasive testing is needed for loosening of dental implants. This study aims to develop the testing method. In this paper, we applied the proposed testing method to an implant like object, which consists of a titanium bolt and a polymethyl methacrylate (PMMA) base block. The tightening torque was also evaluated via the instantaneous frequency of the transmitted pulse in the experimental setups. To provide more detailed analysis, a numerical simulation was performed. This simulation reproduced the experiment by superposing several transmitted pulses where only the PMMA block and both of the block and the titanium bolt. The simulated result showed that the instantaneous frequency of the superposed pulse varied depending on the tightening torque just like the experimental result. However, the variation range of the instantaneous frequency in the simulated result was smaller than the range of the experimental result. It is because identified transmission paths in the simulation were simplified than the real transmission paths. Our future work is to elucidate evaluation mechanism of the proposed method through more detailed simulation.

Journal

Keywords

Details 詳細情報について

  • CRID
    1570291227553663872
  • NII Article ID
    110010054336
  • NII Book ID
    AA11901770
  • ISSN
    13480235
  • Text Lang
    ja
  • Data Source
    • CiNii Articles

Report a problem

Back to top