3. Modeling A#

3.1. Characteristics of modeling#

Plates DKQ and DSQ.

_images/100000000000018C00000201ABA834E0C3713A9F.png

Discretized geometry is shown above. The elements DKQ and DSQ are plane facets with four nodes of type QUAD4. The number of knots on the circumference is 100 and on the length 5.

3.2. Characteristics of the mesh#

Number of knots: 500

Number of meshes and type: 400 QUAD4

3.3. Tested values#

(Frequencies in hertz). Modeling A tests COEF_RIGI_DRZ negative. In this case ddl DRZ has a physical meaning of « drilling rotation » or rotation around the normal to the mean surface.

Mode

Reference

% difference

% difference

ovalization

210.55 210.55

0.44 0.44

—0.46 —0.46

trifoliate

587.92 587.92

1.75 1.75

—0.27 —0.27

off plan

205.89 205.89 588.88 588.88

13.99 13.99 9.75 9.75

—9.49 —9.49

We also test the differences in results between the models DSQ and DKQ.

3.4. notes#

Plate models DKQ and DSQ do not allow out-of-plane modes to be represented correctly. One may think that this is due to the too small number of cells over the length (4 instead of 8 in the reference modeling). The first out-of-plane frequency in plates DSQ should be less than \(200\mathit{Hz}\).