0
Research Papers: Friction & Wear

Effect of Thread and Bearing Friction Coefficients on the Self-Loosening of Preloaded Countersunk-Head Bolts Under Periodic Transverse Excitation

[+] Author and Article Information
Amro M. Zaki, Sayed A. Nassar, Xianjie Yang

Department of Mechanical Engineering, Fastening and Joining Research Institute, Oakland University, Rochester, MI 48309

J. Tribol 132(3), 031601 (Jun 04, 2010) (11 pages) doi:10.1115/1.4001621 History: Received November 03, 2009; Revised April 16, 2010; Published June 04, 2010; Online June 04, 2010

A nonlinear mathematical model is developed for studying the self-loosening behavior of preloaded countersunk threaded fasteners that are subjected to cyclic transverse loads. Torque components acting on the bolt are divided into pitch and resistance torque components; the net torque determines whether or not the bolt will rotate loose under the external excitation. The accumulation of the differential amount of loosening rotation increments is converted into the gradual loss of the bolt tension/clamp load. Although the loosening model incorporates several system variables, this study is focused on investigating the effect of thread and bearing friction coefficients on the loosening of fasteners with coarse and fine threads. Model prediction of the self-loosening behavior is experimentally validated.

Copyright © 2010 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 2

Velocity vector for an arbitrary point Q on the bolt under the head

Grahic Jump Location
Figure 3

Schematic of the bolt head sliding and instantaneous center analysis

Grahic Jump Location
Figure 4

Schematic of the bolt head free body diagram and contact pressure distribution

Grahic Jump Location
Figure 5

Bearing friction torque Tb and bearing shear force Fbs versus the translational-to-rotational speed ratio ηb

Grahic Jump Location
Figure 6

Thread friction torque Tt and thread shear force Fts versus the translational-to-rotational speed ratio ηt

Grahic Jump Location
Figure 7

Bolt bending due to external transverse excitation

Grahic Jump Location
Figure 8

Flow chart for the MATLAB code

Grahic Jump Location
Figure 9

The self-loosening behavior during 1 full cycle

Grahic Jump Location
Figure 10

Self-loosening results for thin coated fasteners (Preload=17.5 kN)

Grahic Jump Location
Figure 11

Self-loosening results for thick coated fasteners (Preload=17.5 kN)

Grahic Jump Location
Figure 12

Self-loosening results for thin coated fasteners (Preload=24.5 kN)

Grahic Jump Location
Figure 13

Self-loosening results for thick coated fasteners (Preload=24.5 kN)

Grahic Jump Location
Figure 14

The effect of the thread friction coefficient μt on the rate of self-loosening

Grahic Jump Location
Figure 15

The effect of the bearing friction coefficient μb on the rate of self-loosening

Grahic Jump Location
Figure 16

Effect of friction combinations on the rate of self-loosening

Grahic Jump Location
Figure 17

Effect of the thread pitch on the self-loosening behavior for fasteners with variable combination (φ=40 deg, μb=μt=0.1)

Grahic Jump Location
Figure 18

Effect of thread pitch on the self-loosening behavior for fasteners with variable combination (φ=49 deg, μb=μt=0.2)

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In