Dynamic Analysis of Slender Marine Structures

Characterization of slender marine structures. Stress analysis and control of local buckling of rigid and flexible pipe cross sections. Effect from buoyancy, internal and external pressure, internal flow. Models for hydrodynamic loads. Modelling of non-linear loads in dynamic analysis. Vortex induced vibrations. Static and dynamic analysis by use of the finite element method. Stochastic analysis in time and frequency domain. Analysis of pipelines on uneven seabeds during installation and operation. Heave compensation of risers. Optimization of catenary risers.

Knowledge: Learn to understand static and dynamic behaviour of slender marine structures and thereby be able to carry out needed analyses for sustainable design and verification of this type of structures. Skills: - understand the term "effective axial force" and how weight, buoyancy, pressure and internal fluid flow will influence effective axial force, axial stresses and local buckling of long pipe structures - be able to carry out calculations of static and dynamic behaviour and local stresses in slender marine structures by use of simple methods and methods based on finite elements - apply analysis models in combination with wave statistics to carry put fatigue analysis and estimation of extreme response - know how vortex induced vibrations will behave and how to calculate this type of response by use of semi-empirical models, and also understand limitations and uncertainties of such models - calculate the behaviour of pipelines during installation - understand how pipelines on the sea floor will behave under the influence of varying pressure and temperature in order to make the right choices with regard to material modelling. - understand the mechanical behavior of complex cross-sections (cables and flexible pipes) wrt. which physical effects that govern the extreme and fatigue responses and be able to predict the governing stresses. General knowledge: - know important applications of slender marine structures such as various types of risers, pipelines, tethers, anchor lines, flexible risers and cabels.

Lectures and exercises. Compulsory project - 3 credits. Ordinary lectures will not be given if number of candidates is three or less. The course must then be taken as a guided self study. Some seminars will be held on subjects of particular interest to the candidates. To pass the course a score of at least 70 percent is required.