Ship's structural design and analysis is of large importance as the basic strength of ship lies on the assessment of its design, the loads it can withstand and the usability of the ship.

Ship Structures, their stresses and deflections

Appropriate specification is the basis of a ship design. A naval architect uses these specifications as guideline to further move on with their project outline, dimensions, layout and to prepare the initial rough draft. Once the initial rough draft is assessed and approved, a preliminary hull design and overview of ship's propulsion is made with progressive changes at each stage. Designs of large and intricate also include sail plans, electrical schematics and the interiors, producing an overall plan for the ship. Ship structures are divided as plate fields, simple beams and complex beam structures. Plate Fields analyzed by Finite Element Modeling takes over both local and global outlook as the stress, deflection and other vibrations can be assessed through local sea pressure and other global stresses and deflections. Simple beams or simple beam structure is analyzed for stress and other deflections through beam analysis software while complex beam structures, both 2D and 3D like side frames, deck frames, longitudinal girders etc is again analyzed by beam modeling software for stress and deflections.

Structural Analysis and its various techniques

Moving to analysis, it can be done through various techniques using spreadsheets, beam modeling, finite element modeling and so on. Spreadsheets, commonly preferred from old days are now used only for the opening calculations and also for one dimensional beam calculations. The usage of spreadsheets is restricted to the preliminary procedure as it is hard to make any modifications according to the changing rules or concerns. When it comes to beam modeling, it's easier to get the stress and deflection at any point down the beam along with the visual view on its reactions and the press button helps to calculate the modal frequencies. Beam modeling preferred in all cases of composite load conditions. While finite element modeling comes with accurate shell plate stresses.