TEST CASE 2.2 NATURAL FREQUENCIES OF A SQUARE PLATE CLAMPED ON ONE SIDE
Reference:
M.V. Barton, “Vibration of rectangular and skew cantilever plates”, Journal of Applied Mechanics, vol. 18, 1951, p. 129 – 134.
Problem description:
Determine the natural frequencies of a square plate clamped on one side.
Problem sketch:
Type of created problem:
Flat plate or grillage (Z, UX, UY).
Geometric characteristics:
a = 1 m; t = 0.01 m.
Material properties:
Elastic modulus: E = 2.1·1011 Pa;
Poisson’s ratio: μ = 0.3;
Density: γ = 7800 kg/m3.
Boundary conditions:
Side АВ: Z = UX = UY = 0.
Loads:
Dead load.
Model description:
The system is modeled using 400 finite elements of thin plate (FE type is 19). To solve the problem, a modal analysis was performed.
Calculation results:
Form № |
Frequency, Hz |
Deviation, % |
|
Analytical solution |
LIRA 10 |
||
1 |
8.7266 |
8.6741 |
0.60 |
2 |
21.3042 |
21.2576 |
0.22 |
3 |
53.5542 |
53.2113 |
0.64 |
4 |
68.2984 |
67.9355 |
0.53 |
5 |
77.7448 |
77.3499 |
0.51 |
6 |
136.0471 |
135.2213 |
0.61 |