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The f i n i t e element method i s used t o study t h e equilibrium and s t a b i l i t y of an e l a s t i c cable whose upper end i s towed i n a horizontal, c i r c u l a r path at a constant angular velocity. i s assumed t o be composed of t a n g e n t i a l and normal components which a r e proportional t o t h e t a n g e n t i a l and normal v e l o c i t y components squared, respectivel y. The problem includes strong geometric nonl i n e a r i t i e s and i s nonconservative, thereby admitt i n g both s t a t i c and dynamic i n s t a b i l i t i e s. Fluid drag Equilibrium equations f o r a cable element including elastogeometric, c e n t r i p e t a l , and aerodynamic s t i f f n e s s matrices a r e developed i n terms of problem parameters and a shape function. A l l geometric n o n l i n e a r i t i e s a r e retained, but small elongations a r e assumed. The r e s u l t i n g nonlinear algebraic equations a r e solved using a Newton-Raphson procedure. The s t a b i l i t y of an equilibrium p o s i t i o n i s determined by perturbing t h e nonlinear equations of motion and calculating t h e eigenvalues of t h e r e s u l t i n g l i n e a r i z e d dynamic equations. Results i n d i c a t e multivalued solutions, t h e number depending on t h e r o t a t i o n a l frequency and tow radius. Both s t a t i c "jump" type and dynamic i n s t a b i l i t i e s a r e found.

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A two-degree-of-freedom lumped-mass model is used to gain understanding of the equilibrium and stability of a circularly towed cable. Particular cases considered are those of no drag, viscous drag, and viscous drag with a crosswind.