Abstract
This is a proposal for the adoption of a simplified means for structural strength calculation based on energy method. Adopting this approach, we may, during initial planning stages, evaluate the strength characteristics of double hull structures by using Lagrange's Multiplier Method to guarantee the continuity of deflection angles with adjoining structures.
The calculation is accomplished by multiplying the nondimensional element stiffness matrix that remains constant for various combinations of structural dimensions by the stiffness ratio. This method makes data inputs and calculation of the stiffness matrix simpler and more expeditious.
The results of calculations using this method have been compared with theoretical values and numerical results obtained through the finite element method (FEM) and have proved to produce results accurate enough to be of practical use, from the perspective of grasping general strength parameters in initial hull planning.Furthermore, we have performed hull structure weight optimization by combining these calculations with genetic algorithms, thereby additionally verifying their validity for the applications addressed here.