A Hybrid Finite Element-Fourier Spectral Method for Vibration Analysis of Structures with Elastic Boundary Conditions

Table 4

Comparison of higher natural frequencies of the rectangular plate.

Mode order	Analytical	FEA^a	ERROR	Hybrid^b	ERROR
10	7.3007	7.2930	0.10%	7.2989	0.02%
20	12.8255	12.8055	0.16%	12.8225	0.02%
30	19.1396	19.0353	0.54%	19.0681	0.37%
40	23.0859	22.8829	0.88%	22.9219	0.71%
50	29.4000	29.0709	1.12%	29.1143	0.97%
60	35.5168	35.1455	1.05%	35.1161	1.13%
70	40.4496	40.0103	1.09%	40.1129	0.83%
80	45.7772	45.2644	1.12%	45.3688	0.89%
90	51.3020	51.0894	0.41%	51.2793	0.04%
100	56.8268	55.60429	2.15%	55.7703	1.86%
200	109.9047	106.3049	3.28%	106.4953	3.10%

Note: FEA results are calculated by using ANSYS with 20 × 40 elements.
^bResults with = = 12 at the FSM zone and 20 × 20 elements at the FEM zone.