| dc.description.abstract | The main objective of this thesis is to conduct a global analysis of a proposed shipping lane for a floating bridge that in future will operate in Halsafjorden. The model is simplified as only the shipping lane will be analysed, and subjected to harmonic regular wave loads. The global model is created and analysed through the FEM software DNV SESAM.
The global model was developed through an internship, at LMG Marin and is based on 2D sketches made in AutoCAD by LMG Marin. The model may as well be applied for other crossings with different requirements, as the model is based on a JavaScript files which are easy to change.
Static equilibrium condition is first determined as to verify positive stability values. This is also done in for damaged conditions where compartments are filled with water, which simulates the effects that follows after a bridge-ship impact.
Waveload analysis is conducted in order to determine how the structure behaves dynamically in the frequency domain. The response amplitude operator is then found and further used to calculate extreme response values through a Rayleigh short term distribution function, which in turn is used to calculate the design wave amplitude.
The waves that induces the greatest responses in terms of acceleration, torsional-, horizontal and vertical bending moment, are further used in a load transfer analysis where loads of the "worst" waves are transferred on the structure. The final result after solving the deformation by the finite element relation, is then processed in order to identify critical areas on the global model in terms of deformations and stresses. The extreme results in the critical areas, are then used in the assessment of improving the model.
Eigenvalue analysis has also be carried out to identify the highest periods and their belonging modeshapes. In addition a sensitivity analysis was done in order to understand how the different mode periods altered.
Different assumptions used in the analysis, and limitations of the software are highlighted and discussed. | en |
