Research Fax
In this memo the natural frequency of the WAFL5412/WALF6312
antenna mast has been calculated, with the aid of the Finite
Element Analysis.
The calculated natural frequencies are compared with the
dominant excitation frequencies. The purpose of the analysis is to
have a margin of 15% between the natural frequency and the
excitation frequencies.
Maximum allowable stressesMaterial: SteelMass density: 8070
kg/m^3Youngs modulus (E): 210000 N/mm^2Poissons ratio:
0.3Excitation frequencies and safety margins
The excitation frequency was considered to be the blade passing
frequency 17.8 Hz.
Analyzed margins of 15% from the excitation were 15.13 - 20.47
Hz.Model
Figure 1: Model overviewConstraints
The constraints are shown in the Figure 2.
Figure 2: Constraints view under deck.Mesh
In the finite element model the mesh has an average size of 36
mm (Figure 3).
Figure 3: The finite element model
Figure 4: Mast drawingThe weight of the Winel vent cap is 6 kg
each.
Analysis ResultsThere are 3 natural frequencies in the range of
15.3 20.47 Hz.
Figure 5: Mode 2, 18.38 HzBlue lines show fixed constraint
Winel vent cap
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