0
Research Papers

Criterion for Preventing Self-Loosening of Preloaded Cap Screws Under Transverse Cyclic Excitation

[+] Author and Article Information
Xianjie Yang

Department of Mechanical Engineering, Fastening and Joining Research Institute, Oakland University, Rochester, MI 48309yang2345@oakland.edu

Sayed A. Nassar

Department of Mechanical Engineering, Fastening and Joining Research Institute, Oakland University, Rochester, MI 48309nassar@oakland.edu

Zhijun Wu

Department of Mechanical Engineering, Fastening and Joining Research Institute, Oakland University, Rochester, MI 48309zwu@oakland.edu

J. Vib. Acoust 133(4), 041013 (Apr 11, 2011) (11 pages) doi:10.1115/1.4003596 History: Received April 01, 2010; Revised September 08, 2010; Published April 11, 2011; Online April 11, 2011

In this paper, a novel criterion is developed for preventing the self-loosening of preloaded threaded cap screws under cyclic transverse loading. For a known cyclic excitation, the system parameters are used in the formulation of a closed form solution for the minimum fastener preload required for preventing self-loosening. The effect of several key variables is investigated; this includes bearing and thread friction coefficients, cap screw grip length, thread pitch, material, and cyclic amplitude of the transverse excitation. An experimental setup and test procedure are established. Comparison between the experimental and analytical clamp load variation results shows that the proposed criterion can accurately predict the requirements for preventing self-loosening.

Copyright © 2011 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Schematic for cap screw joint under transverse cyclic loading

Grahic Jump Location
Figure 2

Relative slippage and friction force on the contact underhead bearing surface

Grahic Jump Location
Figure 3

Correlation between bearing friction torque ratio T¯b and bearing friction shear force ratio F¯bs

Grahic Jump Location
Figure 4

Schematic relative slippage and friction on the contact thread surface

Grahic Jump Location
Figure 5

Correlation between thread friction torque ratio T¯t and transverse thread shear force F¯ts: (a) applied force diagram on the bolt and (b) bending deflection and angle of the bolt

Grahic Jump Location
Figure 6

Schematic of applied force and its deformation of the bolt: (a) applied force diagram on the bolt and (b) bending deflection and angle of the bolt

Grahic Jump Location
Figure 7

Relationship among the ratio Rb, bearing friction coefficient μb, and thread friction coefficient μt for 0.5 in.-13 cap screw (coarse threads): (a) 3D representation of the relations among Rb, μb, and μt and (b) Rb versus μb for various values of μt

Grahic Jump Location
Figure 8

Relationship among the critical ratio Rb, bearing friction coefficient μb, and thread friction coefficient μt for 0.5 in.-20 cap screw (fine threads): (a) 3D representation of the relations among Rb, μb, and μt and (b) Rb versus μb for various values of μt

Grahic Jump Location
Figure 9

Effect of bearing friction coefficient on the ratio Rb

Grahic Jump Location
Figure 10

Experimental cap screw tension variation for determination of the required preload levels under external cyclic excitation amplitude δ0=0.3556 mm

Grahic Jump Location
Figure 11

Effect of thread pitch on the threshold preload for preventing self-loosening (steel cap screw, δ0=0.7 mm, and L=60 mm)

Grahic Jump Location
Figure 12

Effect of bearing friction coefficient μb and thread friction coefficient μt (0.5 in.-13 steel cap screw, L=63 mm, and δ0=0.7 mm)

Grahic Jump Location
Figure 13

Effect of bearing friction coefficient on the threshold preload for preventing self-loosening (0.5 in.-13 aluminum alloy cap screw, δ=0.7 mm, and L=70 mm)

Grahic Jump Location
Figure 14

Effect of Young’s modulus of cap screw material on the threshold preload (0.5 in.-13 steel cap screw, δ=0.7 mm, L=60 mm, and μb=0.16±0.02)

Grahic Jump Location
Figure 15

Effect of the cap screw grip length on the threshold preload (0.5 in.-13 steel cap screw, δ=0.7 mm, and μb=0.125±0.02)

Grahic Jump Location
Figure 16

Effect of external cyclic excitation amplitude δ0 on the threshold preload (0.5 in.-13 steel cap screw, L=70 mm, and μb=0.15±0.02)

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