Accession Number : ADA268458


Title :   Investigation of the Dynamics of Low-Tension Cables


Descriptive Note : Doctoral thesis,


Corporate Author : WOODS HOLE OCEANOGRAPHIC INSTITUTION MA


Personal Author(s) : Howell, Christopher T


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a268458.pdf


Report Date : Jun 1992


Pagination or Media Count : 154


Abstract : Low-tension cable problems are particularly complex as linear solutions are unobtainable in most cases, due to the lack of a meaningful static configuration. By contrast, the dynamics of taut cables are only weakly nonlinear. First, the three-dimensional nonlinear equations of motion and compatibility relations are formulated for a cable with bending stiffness. Forces in bending are included to provide the necessary physical mechanism for energy transfer across isolated points of zero tension and to ensure a smooth cable configuration. The mechanisms for low-tension response to excitation are explored by considering the limiting case of a cable with zero initial tension, subject to an impulsive force at one end. The three-dimensional equations show the development of impulsive tension. The intensity of the tension and the velocity components depend exclusively on the initial curvature and are independent of the geometric torsion. In addition, singularities are found to develop at points of curvature discontinuity. Incorporating the cable's bending stiffness removes these singularities by ensuring smooth curvature. However. sustained boundary layers are found to develop, demonstrating the importance of the underlying physical mechanism. The transition from taut to low-tension behavior is examined through an analysis of the dynamics of a hanging chain, driven by planar harmonic excitation at the top. For moderately large excitation amplitudes, asymptotic results demonstrate the existence of distinct regions of stable two-dimensional and stable three-dimensional response, as a function of frequency, as well as a distinct region in which all steady state solutions are found to be unstable. ... Low-tension, Cables, Bending stiffness.


Descriptors :   *DYNAMICS , *CABLES , *TENSION , *NONLINEAR ANALYSIS , FREQUENCY , FUNCTIONS , STEADY STATE , STIFFNESS , COMPATIBILITY , ENERGY TRANSFER , THREE DIMENSIONAL , COLLAPSE , TORSION , STATICS , AMPLITUDE , DISCONTINUITIES , BEHAVIOR , CONFIGURATIONS , CURVATURE , BENDING , BOUNDARY LAYER , INTENSITY , HARMONICS , TWO DIMENSIONAL , CONTRAST , EQUATIONS OF MOTION


Subject Categories : Theoretical Mathematics
      Mechanics


Distribution Statement : APPROVED FOR PUBLIC RELEASE