Paper Title:
Ultrasonic Stress Measurement: Application to Preload Assessment on Already Tightened Bolts
  Abstract

When a material is under mechanical load, the stresses modify the velocity of acoustic waves. This consists in acoustoelastic effect. This property can be exploited for stress measurement in the material itself when the stress concerns the surface of the material, or in the bulk material, as in bolts. The ultrasonic bolt tightening control allows knowledge of preload stress in screws. The accuracy is much better than in the case of torque wrench. In fact, the use of this mechanical-based measurement equipment leads to uncertainties due to random resistant torques, induced by mechanical manufacturing tolerances. The ultrasonic measurement of the pre-load gives the information about the tension inside of the bolt, independently of mechanical uncertainties. This consists in an in-situ measurement. More, in some cases, the ultrasonic method allows knowledge of the preload on bolts already tightened, without untightening. This method is called bi-wave method, and has many connections with birefringent method. Examples of application of the method are presented about the differential mode case, which is largely known and industrialized, and in the case of bi-wave method, which lead to several on site applications, performed by CETIM with a prototype equipment.

  Info
Periodical
Materials Science Forum (Volumes 524-525)
Edited by
W. Reimers and S. Quander
Pages
459-464
DOI
10.4028/www.scientific.net/MSF.524-525.459
Citation
H. Walaszek, P. Bouteille, "Ultrasonic Stress Measurement: Application to Preload Assessment on Already Tightened Bolts", Materials Science Forum, Vols. 524-525, pp. 459-464, 2006
Online since
September 2006
Export
Price
$32.00
Share

In order to see related information, you need to Login.

In order to see related information, you need to Login.

Authors: Youn Ho Cho, Moogeun Kim
396
Authors: Shiuh Chuan Her, Sheng Tung Lin
Abstract:Ultrasonic is one of the most common uses of non-destructive evaluation technique. It could detect flaws inside the structure and on the...
865
Authors: Fu Jin Yu, Lin Lin Wang
Chapter 1: Material Section
Abstract:In this paper, the surface residual stress of spheroidal graphite cast iron was measured by using critically refracted longitudinal (LCR)...
409
Authors: Claudio Nucera, Robert Phillips, Francesco Lanza di Scalea
Chapter 4: Structural Health Monitoring and Control
Abstract:Among structural concerns for the safety of rail transportation are internal flaws and thermal stresses, both of which can cause disruption...
198
Authors: Jiri Brozovsky, Lenka Bodnárová, Rudolf Hela, Rostislav Drochytka, Vlastimil Hela
Chapter 4: Architecture, Civil and Industrial Engineering
Abstract:Ultrasonic pulse method is a non-destructive testing method used for testing materials. For concrete, it is used mostly for determination of...
1315