OS-V: 0435 Clamped Thick Rhombic Plate
Test No. FV22 The behavior of distorted, thick elements in normal modes analysis is examined using OptiStruct.
Figure 1. FE Model with Boundary Conditions and Loadcases
Benchmark Model
The 4-node quad elements with 10x10 mesh configuration are used to model the thick rhombic plate. The x-translation, y-translation displacements, and z-rotational displacements are fixed for all of the nodes. In addition, the z-translation, x-rotational and y-rotational are fixed for the nodes along the four edges.
The material properties are:
- Property
- Value
- E
- 200 x 109 N/m2
- 0.3
- 8000 kg/m3
Modal Analysis Results
The frequency of each targeted mode is normalized with the closed form solution. The closed form
solution is not available for mode 6, the target value for H.O.E. should be used
instead.
f*- Closed form solution
| Mode 1 | Mode 2 | Mode 3 | |||
|---|---|---|---|---|---|
 |
|
 |
|||
f*CQUAD4 |
133.95 Hz 0.9937 |
f*CQUAD4 |
201.41 Hz 1.0382 |
f*CQUAD4 |
265.81 Hz 1.0633 |
| Mode 4 | Mode 5 | Mode 6 | |||
|---|---|---|---|---|---|
 |
|
 |
|||
f*CQUAD4 |
283.68 Hz 1.0006 |
f*CQUAD4 |
334.45 Hz 1.1073 |
F[HOE] CQUAD4 |
386.62 Hz 1.0403 |
Model Files
The model files used in this problem include:
- <install_directory>/hwsolvers/demos/optistruct/verification/fv22.fem
Reference
NAFEMS Ltd, The Standard NAFEMS BENCHMARKS TNSB Rev. 3, NAFEMS Ltd, Scottish Enterprise Technology Park, Whitworth Building, East Kilbride, Glasgow, United Kingdom, 1990.