About Effective Stiffness of the Flexibility Couplings of Lengthy Dynamic System in the Flow

On the base of wellknown results of mechanics, concerned to configuration and pliability of cable-rope system, as well as loaded bended (catenary) couplings of dynamic system, the problem of caterary stiffness is investigating. Catenary stiffness (stipulated by changes of configuration of flexibility coupling) is more important, in determinate conditions, than natural stiffness of the same couplings, which stipulated by elasticity of material. The analytical results are illustrating by the examples of calculation of the equivalent stiffness and the own dynamical characteristics technical systems of lifting and towing deepwater objects, in particular remotely controlled underwater robots. These results may be used in the analysys of dynamic underwater manipulator systems, as well as in the analysys of lengthy mechanical systems which are functioning in continuous mediums.