2. Benchmark solution#
2.1. Calculation method used for the reference solution#
The reference solution is the one given in sheet SDLS01 /89 of the guide VPCS which presents the calculation method as follows:
The formulation of M.V. BARTON, for a \(a\) side plate, leads to:
\({f}_{i}=\frac{1}{2\pi {a}^{2}}{\lambda }_{i}^{2}\sqrt{\frac{{\mathrm{Et}}^{2}}{12\rho (1-{\nu }^{2})}}\) \(i=\mathrm{1,2},\mathrm{...}\)
with, for a Poisson’s ratio \(\nu =0.3\):
1°: Plate embedded on one side |
2°: Free plate |
\(i\) |
|
\(i\) |
|
|
1 |
3.492 |
1 to 6 |
||
2 |
8.525 |
7 |
13.49 |
|
3 |
21.43 |
8 |
19.79 |
|
4 |
27.33 |
9 |
24.43 |
|
5 |
31.11 |
10 |
35.02 |
|
6 |
54.44 |
11 |
35.02 |
(6 solid body modes at zero frequency).
This reference solution applies to thin plates such as: \(t/a<0.1\)
The coefficients \({\lambda }_{i}\) are established by limited development on the modal deformations of a network of crossed beams (embedded beam—free and free—free).
2.2. Benchmark results#
Case 1:6 first clean modes
Case 2:11 first natural modes
2.3. Uncertainty about the solution#
Semi—analytical solution.
2.4. Bibliographical references#
M.V. BARTON Vibrations of rectangular and skew cantilever plates. — Journal of Applied Mechanics, vol18, p.129—134 (1951)