By M. G. Donley, P. D. Spanos (auth.)
1. 1 advent As offshore oil creation strikes into deeper water, compliant structural structures have gotten more and more very important. Examples of this sort of constitution are pressure leg platfonns (TLP's), guyed tower platfonns, compliant tower platfonns, and floating creation structures. the typical characteristic of those structures, which distinguishes them from traditional jacket platfonns, is that dynamic amplification is minimized by way of designing the surge and sway average frequencies to be under the most important frequencies of the wave spectrum. traditional jacket platfonns, however, are designed to have excessive stiffness in order that the ordinary frequencies are larger than the wave frequencies. At deeper water depths, although, it turns into uneconomical to construct a platfonn with excessive adequate stiffness. hence, the change is made to the opposite part of the wave spectrum. The low traditional frequency of a compliant platfonn is accomplished by way of designing structures which inherently have low stiffness. as a result, the utmost horizontal tours of those platforms could be very huge. The low traditional frequency attribute of compliant structures creates new analytical demanding situations for engineers. the reason is, geometric stiffness and hydrodynamic strength nonlinearities could cause major resonance responses within the surge and sway modes, although the ordinary frequencies of those modes are open air the wave spectrum frequencies. excessive frequency resonance responses in different modes, reminiscent of the pitch mode of a TLP, also are possible.