Design 



Environmental Loads on Structures . The design for OTEC structures 

 to resist environment loads will be only as accurate as the input loading 

 data. Oceanographic and meteorological data need to be compiled from 

 probable operational sites so that valid historical data are available on 

 currents, waves, and wind. The dominant environment load is from waves, 

 and analytical techniques exist to predict forces due to waves. The pre- 

 dictions are based on wave scatter diagrams that cover significant wave 

 heights and zero crossing periods that enable both maximum and cumulative 

 forces to be assessed for static and dynamic conditions. 



Structural Analysis Methods . Once the environmental loads are deter- 

 mined, the forces within the structure may be calculated. Powerful analytical 

 methods exist, namely finite element and finite difference techniques, to 

 predict the response of structures to external loads. The internal forces, 

 stresses, deflections, and strains are predicted well for linear and non- 

 linear materials. Limitations on these methods are the accuracy of input 

 data on material behavior and skill of the structural analyst in subdividing 

 the structure into elements. 



Design for Hydrostatic Loading . Studies on pressure-resistant con- 

 crete structures have been directed at developing design approaches to 

 predict implosion strength. For cylinder structures, research on the 

 effects °f length to diameter, wall thickness to diameter, and different 

 types°f en d closures has been conducted. Design guides have been pub- 

 lished in the form of a handbook. L* 2 J 



Several deficiencies exist in the available design procedures when 

 related to OTEC structures. No studies have been conducted on the effect 



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