Assignment:
By using HyperMesh software, make a beam model similar to the below test model and find (Using Nastran) the mode shapes and resonances of the model.
Make your model with three following modelling methods:
1. Using 1-D BEAM Elements,
2. Using 2-D SHELL Elements, and
3. Using 3-D SOLID Elements.
Compare the mode shapes and resonances of the three modelling methods. Explain the reasons for possible slight discrepancies between different modelling methods.
Note: I suggest you to make a table and compare the corresponding resonant frequencies for 1D Beam, 2D SHELL, and 3D SOLID elements modelling methods (Six structural modes for each method are sufficient).
**A maximum 4 pages (including figures) report is sufficient.
**Submit your Homework on Learning Hub (Online) in PDF format, do not submit to reception.
Attention:
The below test results are only for your reading and information. My undergraduate students of Vehicle NVH course have conducted the below tests on the same size beam.
You may compare your own CAE results with the blow test results.
POLYETC LASER VIBROMETER (Notes about the experiment)
1. Beam material: Aluminium (Al), Width (W) = 50mm, Length (L) = 600mm' Thickness (t) = 10mm.
2. Apparatus for experiment:
2. Measurement results:
1) Resonances
|
Mode #
|
Measurement (Hz)
|
|
1
|
153.5
|
|
2
|
411.5
|
|
3
|
-
|
|
4
|
811.0
|
2) Model Shapes:
153.5 HZ
411.5 Hz
811.0 Hz