1. Design assessment of dynamic amplification What is measured?
Classification: Statoil internal Status: Draft
Kvitebjørn Jacket
Design assessment of dynamic amplification What is measured?
Sverre Haver, Statoil 13/

2. Photo: Halvor Arne Asland

3. Wave climate
Platform substructure

4. Top side mass
Second order surface process is simulated
Linear springs model platform-soil system

5. First step – eigenvalue analysis
Simulated sea states

6. Quasistatic and dynamic simulation for hs=14.9m and tp=16s.
A considerable resonant response is observed.
Gumbel model fitted to sample

11. It is seen for fatigue purposes one may generally utilize a frequency domain analysis. Exception members close to the free surface.

14. What have we experienced
Platform largest natural period is 4s instead of 5s. (Most likely to lower deck weigth than used in design and conservative modelling of stiffness.)
We typically measure less dynamic response. It seems as if we are overestimating the super-harmonic exitation.
Some few episodes with large response can we not reproduce.