Dynamic response analysis of ship hull structures

Finite-element modeling and use of appropriate analytical techniques play a significant role in producing a reliable and economic design for ship hull structures subjected to dynamic loading. The paper presents investigations carried out for the dynamic response analysis of ship hull structures usin g the finite-element method. A simple and efficient interactive graphical p reprocessing technique based on the "keynode" concept and assembly-line pro cedure is used to develop the finite-element model of the hull structure. T he technique makes use of the body plan of a ship hull to build the finite- element model through an interactive session. Stiffened plate/shell finite elements suitable to model the hull structure are formulated and used to mo del the structure. The finite elements take into account arbitrary placemen t of stiffeners in an element without increasing the number of degrees-of-f reedom of the element. A three-dimensional finite-element model and a proce dure based on the Bubnov-Galerkin residual approach are employed to evaluat e the effects of interaction between the ship hull and water. Mode superpos ition technique is used to conduct the dynamic response analysis. The effic iency of the finite elements and the procedures is demonstrated through dyn amic analysis of a submerged cantilever plate and a barge when both are sub jected to sinusoidal forces. The dynamic responses exhibit expected behavio r of the structure and a comparison with the results available in the liter ature indicate superior performance of the finite element and methodologies developed. Thus, the finite-element models and the procedures are found to be efficient and hence suitable for the dynamic analysis of similar struct ures.