TEST CASE 2.3 EIGENFREQUENCIES OF RECTANGULAR PLATE SIMPLY-SUPPORTED ON ALL EDGES
Reference :
M.V. Barton, “Vibration of rectangular and skew cantilever plates”, Journal of Applied Mechanics, vol. 18, 1951, p. 129 – 134.
Problem sketch:
Fig. 2.3
Type of created problem:
Flat plate or grillage ( Z , UX
, UY).
Input data:
;
;
;
Material properties:
Isotropic elastic:
;
;
Boundary conditions:
Across perimeter:
;
Problem description:
System was modeled using finite elements of thin plate (FE 19).
Mesh: 20x20 FE - classic analysis; 10x10 FE - analysis using finite elements with intermediate nodes.
Modal analysis has been performed to solve the problem.
Calculation results:
Table 2.3
# of mode |
Frequency, Hz |
Deviation, % |
|
Analytical solution |
Solution results by LIRA 10.4 |
||
1 |
35.63 |
35.573 (35.624) |
0.16 (0.02) |
2 |
68.51 |
68.327 (68.506) |
0.27 (0.01) |
3 |
109.62 |
109.381 (109.600) |
0.22(0.02) |
4 |
123.32 |
122.933 (123.305) |
0.32(0.01) |
5 |
142.51 |
141.665 (142.474) |
0.6 (0.03) |
6 |
197.32 |
195.591 (197.267) |
0.88 (0.03) |
- solution results using finite elements with intermediate nodes are specified within the brackets.