An Analysis of Coupled Extensional-Torsional Oscillations in Wire Rope

[+] Author and Article Information
R. K. Samras, R. A. Skop, D. A. Milburn

Ocean Technology Division, Naval Research Laboratory, Washington, D. C.

J. Eng. Ind 96(4), 1130-1135 (Nov 01, 1974) (6 pages) doi:10.1115/1.3438486 History: Received July 31, 1973; Online July 15, 2010


Coupled extensional-torsional behavior of wire rope is considered. Equations of motion for a straight rope section loaded simultaneously in tension and torque are derived, and constitutive equations relating these loadings to extensional and rotational deformations of the rope are postulated. A pair of wave equations describing coupled extensional-torsional oscillations of a wire rope is then obtained. The solution to these equations shows that, in general, two types of waves can propagate through a straight rope section. Four commonly occurring boundary value problems for a rope stretched between the ocean floor and ocean surface are considered. Each problem has a different combination of end restraints—either clamped or swiveled. A sinusoidal forcing function representing wave action is applied to the upper end of the rope. The critical driving frequencies as a function of rope length are calculated for each boundary value problem. These critical frequencies are compared with those predicted by considering extensional oscillations only. The comparison shows that significant differences exist bewteen the predicted resonant frequencies and demonstrates the importance of examining the torsional behavior of wire rope.

Copyright © 1974 by ASME
Your Session has timed out. Please sign back in to continue.






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