lonelytown
Civil/Environmental
- Jul 26, 2012
- 3
If we want to consider VIV issues for submerged structures, we need to calculate the in-line and cross-flow frequencies of the pipeline/jumper/riser. Caesar II have mode analysis and can provide the natural frequencies of the structure.
As we learnt from classical vibration mechanics, the natural frequencies of structural are the inherent properties of structures as well as vibration modes. They should be constant irrespective to the loads.
However, when I change the load case of the structures in Caesar II, the natural frequencies change.
Secondly. We know each natural frequency is associated with one particular mode. If we are talking about In-line and cross-flow frequencies, we need to know the modes first. However, Caesar II only provides a series of frequencies without any further information.
Can you share your experience?
As we learnt from classical vibration mechanics, the natural frequencies of structural are the inherent properties of structures as well as vibration modes. They should be constant irrespective to the loads.
However, when I change the load case of the structures in Caesar II, the natural frequencies change.
Secondly. We know each natural frequency is associated with one particular mode. If we are talking about In-line and cross-flow frequencies, we need to know the modes first. However, Caesar II only provides a series of frequencies without any further information.
Can you share your experience?
