Flight Loads Prediction of High Aspect Ratio Wing Aircraft Using Multibody Dynamics

Table 4

Natural frequencies of the free-free aircraft under trim loads: linear FEM versus multibody (Method B).

Mode description	3D FEM – frequency [Hz]					Multibody – frequency [Hz]
	0 g	1 g	1.5 g	2 g	2.5 g	0 g	1 g	1.5 g	2 g	2.5 g
1st symm. bending	0.836	0.851	0.867	0.887	0.910	0.833	0.848	0.864	0.884	0.907
2nd symm. bending	2.059	2.076	2.095	2.118	2.144	2.045	2.059	2.080	2.097	2.123
1st symm. mixed bending + VT torsion/HT bending	3.640	3.739	3.754	3.766	3.775	3.607	3.646	3.649	3.657	3.673
3rd symm. bending + torsion	3.710	3.364	3.204	3.134	3.106	3.625	3.327	3.169	3.091	3.066
1st in-plane bending + fuselage/HT bending	4.019	4.197	4.253	4.292	4.322	3.971	4.147	4.193	4.232	4.257