OS-V: 0210 Simply-Supported Thick Square Plate
Test 21OptiStruct is used to investigate the repeated eigenvalues and the effect of ‘secondary’ restrains.
図 1. FE Model with Boundary Conditions and Loadcases
Benchmark Model
The 2nd order and 1st order quad elements are used to model the square plate of thickness 1.0m. The z-rotation and x, y translations are fixed for all the nodes, z-translation is fixed along all four edges, x-rotation is fixed along the edge x=0 and x=10 and y-rotation is fixed along the edge y=0 and y=10.
The material properties are:
- Material Properties
- Value
- Young’s Modulus
- 200 × 109 N/m2
- Poisson’s Ratio
- 0.3
- Density
- 8000 kg/m3
Modal Analysis Results
The frequency of each targeted mode is normalized with the closed form solution.
f*- Closed form solution
| Mode 1 | Modes 2 and 3 | Mode 4 | |||
|---|---|---|---|---|---|
|
|
|
|||
f* |
45.897 Hz | f* |
109.44 Hz | f* |
167.89 Hz |
| HOE | 1.013827837 | HOE | 1.044863043 | HOE | 1.046793653 |
| LOE | 1.005851414 | LOE | 1.002363027 | LOE | 1.034589005 |
| Modes 5 and 6 | Modes 7 and 8 | ||
|---|---|---|---|
|
|
||
f* |
204.51 Hz | f* |
256.50 Hz |
| HOE | 1.125821617 | HOE | 1.094829757 |
| LOE | 0.993823531 | LOE | 1.051061511 |
Model Files
必要なモデルファイルのダウンロードについては、モデルファイルへのアクセスを参照してください。
The model files used in this problem include:
- Test21HOE.fem
- Test21LOE.fem
Reference
NAFEMS R0015 - Selected benchmarks for natural frequency analysis