Free Vibration Analysis of Rotating Pretwisted Functionally Graded Sandwich Blades

Table 5

Comparisons of nondimensional frequency parameters for the first six modes of the FG sandwich blade (, , , and ).

Mode	0°				15°				30°
	Present	ANSYS	Error	Mode shape	Present	ANSYS	Error	Mode shape	Present	ANSYS	Error	Mode shape
1st	4.5233	4.5270	−0.08%	1B	4.5206	4.5272	−0.15%	1B	4.4729	4.5290	−1.24%	1B
2nd	27.9633	27.7729	0.69%	1 T	27.4621	27.3966	0.24%	2B	25.4167	25.0992	1.26%	2B
3rd	28.3106	28.2605	0.18%	2B	29.1565	29.0406	0.40%	1T	33.0633	32.5549	1.56%	1T
4th	75.9386	75.8281	0.15%	1 EB	74.8841	76.2376	−1.78%	3B	73.0937	72.9145	0.25%	3B
5th	79.3035	79.1454	0.20%	3B	82.0284	80.3331	2.11%	1EB	89.2792	88.7755	0.57%	1EB
6th	87.5852	87.0515	0.61%	2 T	90.5827	89.9847	0.66%	2T	99.5237	98.9166	0.61%	2T