Catalog Description

EN358: Ship Structures (3-2-4).

Topics include dimensional analysis, similitude, wave and viscous resistance of ships, ship-model testing techniques, full-scale performance prediction, momentum theory of propulsion devices and propeller A course in structural theory and practice. Topics include longitudinal and transverse strength of the hull girder, bending moments in a seaway, plate theory, development of a ship’s structural design, submarine pressure hull design, and shipbuilding materials. 

Prereq: EM217 and EN342

Textbook

Miller, P.H. and Stettler, J.W., EN358 Ship Structures: Notes for an Undergraduate Course, Naval Architecture and Ocean Engineering Department, U.S. Naval Academy, 2010

References

1. Hughes, O.F., Ship Structural Design: A Rationally-Based, Computer-Aided, Optimization Approach, Society of Naval Architects and Marine Engineers (SNAME), Jersey City, NJ, 1988.
2. Rules for Building and Classing Steel Ships, American Bureau of Shipping, 2009
3. Structural Design Manual for Naval Surface Ships, NAVSEA 0090-LP-097-4010, Naval Sea Systems Command, 1976.

Course Coordinator

Professor G. White

Goals

1. Perform a preliminary structural design of a ship. This includes demonstrating a basic understanding of the sources of structural loads, types and control of material stresses, primary and secondary structural failure modes, classification society rules, factors of safety, and materials selection.
2. Apply basic hull girder analysis for the design of a ship structure, including calculations of vertical global hull girder bending loads, section modulus, and bending stresses.
3. Apply basic concepts of shear stresses in ship primary and tertiary structures, including shear flow and shear lag effects.
4. Apply basic concepts for the bending of beams, plates, and stiffened panels as applied to a ship structure.
5. Apply basic concepts for the buckling of columns, plates, and stiffened panels as applied to a ship structure.
6. Apply basic concepts of matrix stiffness and finite element analysis (FEA) as applied to a ship structure.

Prerequisites

1. EN221/EN222 Engineering Mechanics with Marine Applications I/II, NAOE Department
2. EN380 Naval Material Science and Engineering, NAOE Department
3. EN342 Hydrostatics and Stability, NAOE Department

Class Topics

1. Ship structural components and loads
2. Quasi-static hull girder analysis
3. Random Loads and Fatigue
4. Frame analysis using matrix methods
5. Plate theory and design
6. Beam-Column analysis and design
7. Plate buckling
8. Stiffened-panel theory and design
9. Preliminary structural design of a midship section

Computer Usage

The students are required to make extensive use of the capabilities of their spreadsheet program for this course. Advanced features such as conditional logic, table lookup, intrinsic functions, and optimization are introduced and utilized. The students are required to develop spreadsheets for finding the section modulus of an entire midship section of a ship. The students are also encouraged to use their spreadsheet program to solve the design equations in a systematic form so that they can try different combinations of variables in order to do some basic optimization of their design.

Laboratory Projects

1. Class Exercise: Sub-component structural analysis
2. Class Exercise: Boundary Conditions
3. Class Exercise: Weight curve development
4. Computer Exercise: Hull girder analysis using first principles and hydrostatics software
5. Laboratory Project: 4-point beam bending
6. Computer Exercise: Finite Element Analysis (4 labs)
7. Laboratory Project: Stiffened panel under combined loads
8. Design Problem: Midship Section Design (5 labs)