Vibration analysis
ScanVibra performs
vibration review, analysis,
calculations and predictions for
wide range of vessel types. The
vibration analysis of newbuildings
serves to avoid problems in terms of
comfort on board, as well as damage
to structure or equipment.
The risk of excessive
vibration is strongly related to
resonance problems. Thus, a main
focus in vibration analysis is to
ensure that no critical hull
structure natural frequencies
coincide with the most important
excitation frequencies.
For calculations, the
Finite Element (FE) method is
applied, using models comprising all
relevant structures: Decks,
bulkheads, shell, girders, beams and
pillars. Local and global
calculation models can be used: It
is always required to perform local
calculations of e.g. deck structures
in order to avoid resonance
problems. These local calculations
are usually based on 2-dimensional
FE models.
Depending on the
vessel characteristics and the
strictness of the vibration
requirements, it can be decided to
perform also global 3-dimensional FE
calculations. In addition to natural
frequency analysis, the global
calculations allow for prediction of
the vibration levels induced for
example by the propellers.
The FE calculation
method is well suited for the
simulation of various vibration
reducing measures - such as reduced
propeller pressure pulsations,
stiffening proposals etc.
