Differential Equations of Motion for Naturally Curved and Twisted Composite Space Beams

Table 1

The first five frequencies of Beam 1 (made of isotropic material).

Mode number (Hz)	FEM	Present study (PS)
		Warping ignored	Errors (%)	Warping included	Errors (%)
1	521.34	745.84	43.06	523.25	0.37
2	899.54	1009.30	12.20	897.71	0.20
3	915.97	1044.17	13.99	914.36	0.17
4	970.21	1122.22	15.67	973.88	0.38
5	1129.5	1338.65	18.52	1118.41	0.98