NA21004 Ship Strength

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Course info

Credit: 4 Units (3-1-0).

Instructor: Dr. Md Rushdie Ibne Islam, Email: mrii@naval.iitkgp.ac.in, Office: 214 (Dept. of Ocean Engg. & Naval Architecture).

Class timings:

• Lecture: Monday, 12 Noon – 1 PM; Tuesday, 10 AM – 12 Noon; NC412
• Tutorial: Thursday, 8 AM – 9 AM; NC412

TAs: Kamlesh Behera, Guguloth Hemanth

Office hours: Either stop by instructor's office (for quick discussion) or take an email appointment (for longer discussion).

Important note: Please include NA21004 (without space) in the subject line for all email communications related to this course.

Syllabus

• Part I: Ship Structural System and Hull Girder Idealization
  • Introduction to ship structures:
    • Structural components of ships.
    • Primary, secondary and tertiary structural members.
    • Longitudinal and transverse framing systems.
    • Load paths in ship structures.
    • Forces acting on ship structure:
      • Still-water loads.
      • Wave-induced loads.
      • Cargo loads.
      • Ballast loads.
      • Hydrostatic and hydrodynamic forces.
    • Idealization of ship structure as a hull girder.
    • Assumptions in beam idealization.
    • Applications.
• Part II: Longitudinal Strength of Ships
  • Longitudinal bending of hull girder:
    • Weight distribution.
    • Buoyancy distribution.
    • Load curves.
    • Still-water loading conditions.
    • Wave loading conditions.
  • Hull girder response:
    • Shear force diagrams.
    • Bending moment diagrams.
    • Deflection of hull girder.
    • Hogging and sagging conditions.
    • Interpretation of structural response.
  • Section properties:
    • Neutral axis.
    • Moment of inertia.
    • Section modulus.
    • Calculation of equivalent section properties.
  • Hull girder stresses:
    • Bending stresses.
    • Effect of shear force in bending.
    • Shear stresses.
    • Stresses under inclined loading conditions.
    • Combined loading.
  • Longitudinal strength standards:
    • Allowable stresses.
    • Strength criteria.
    • Introduction to classification society requirements.
• Part III: Structural Components and Local Strength
  • Analysis of decks and bulkheads:
    • Functions of decks and bulkheads.
    • Load transfer mechanisms.
    • Idealization as beams and plates.
    • Structural response under pressure loading.
  • Structural discontinuities:
    • Openings in ship structures.
    • Cut-outs and hatch openings.
    • Stress concentration.
    • Methods for stress reduction.
  • Beam and frame analysis:
    • Ship frames and stiffeners.
    • Introduction to stiffness method.
    • Member stiffness matrices.
    • Assembly procedure.
    • Applications to ship structural members.
• Part IV: Elasticity and Plate Bending
  • Introduction to elasticity:
    • Stress and strain.
    • Generalized Hooke's law.
    • Plane stress assumption.
    • Constitutive relations.
  • Plane stress problems:
    • Stress transformation.
    • Principal stresses.
    • Maximum shear stress.
    • Applications to ship structures.
  • Plate bending:
    • Thin plate assumptions.
    • Plate bending under transverse loading.
    • Rectangular plates.
    • Boundary conditions.
    • Applications to deck, bottom and bulkhead plating.

References

• Primary
  • Eric C Tupper. Introduction to Naval Architecture.
  • Alaa Mansour and Donald liu. The Principle of Naval Architecture Series: Strength of Ships and Ocean Structures.
• Additional
  • K J Rawson and E C Tupper. Basic Ship Theory.
  • Mohamed Shama. Torsion and Shear Stresses in Ships.
  • Mohamed Shama. Buckling of Ship Structures.
  • Owen Hughes and Jeom K Paik. Ship Structural Analysis and Design.
  • IRS – Rules and Regulations for the Construction and Classifications of Steel Ships
  • DNV-RU-SHIP, Part 3, Chapter 5, Hull Girder Strength

Class tests, Mid and End semester exams

• Four class tests will be conducted; two (class tests #1 and #2) before and another two (class tests #3 and #4) after the mid semester exam. Exact date, time and place will be notified later.
• Mid and End semester exams will be scheduled based on the institute timetable.

Homework

• Homework will be assigned almost every week. These will not be graded. Hence, submission is not necessary.
• A subset of problems from homework will be discussed/solved during tutorial sessions and solutions of the remaining problems will be provided.
• Students are strongly encouraged to try the homework problems before coming to the tutorial sessions.

Attendance

• Students are strongly encouraged to attend all the lecture and tutorial sessions. Attendance will be recorded for each lecture session.