Course content

Accidental action from ship collision (with other ships, platforms and bridges), grounding, falling objects, explosions, fires, abnormal environmental loads, earthquakes, residual strength of damaged structure. Design philosophy with particular reference to rules for the North Sea. Fundamental theory for elasto-plastic and ideal plastic analysis including large deformation effects and elevated temperatures. The theory behind the nonlinear 3D frame program USFOS . Presentation of practical design methods is emphasized. Calculation examples, partly computer based using USFOS.
The basis for design against accidental actions according to NORSOK Standard N-004 is reviewed in detail.

Learning outcome

After completed course the students shall have acquired knowledge of the mechanical behavior during progressive collapse of marine structures subjected to accidental actions and knowledge of fundamental principles for design against these actions. Further they shall have knowledge about the theory behind computer program USFOS.The shall be capable of:
- Describe the physical characteristics of the most common failure modes
- Construct simple collapse mechanisms and on the basis of these calculate the ultimate capacity, the energy dissipation, deformation and damage for various accidental actions, such as ship collision, explosions and dropped objects
- On the basis of simple considerations assess the effect of dynamically applied actions
- Perform simple calculations of heat transfer for fire exposed strcutures and assess the degradation of the structural resistance at elevated temperatures
The students shall have acquired skills in use of advanced nonlinear finite element analysis of realistic accident scenarions for various marine - (platforms, ships) or landbased strcutures.

Learning methods and activities

Lectures, calculation exercises, computer exercises, project work (detailed analysis of structural response to accidental action).

Compulsory assignments

• Project
• Exercises

Recommended previous knowledge

TMR4205 Buckling and Collapse, TMR11 Structural Analysis or corresponding knowledge

Course materials

Text book: "Nonlinear Analysis of Offshore Structures" by B. Skallerud and J. Amdahl, Research Studies Press, UK, 2002.
Lecture notes and journal and conferense papers.

Credit reductions