A Multimode Approach to Geometrically Nonlinear Free and Forced Vibrations of Multistepped Beams

Table 2

The frequency differences and residual for each value of a₁ and at different numbers of basic functions.

Basic function numbers
Test	a1		7	8	9	10
1	0.5	1.23	1.45E−05	1.80E−07	2.90E−07	1.00E−08	1.452E−05
2	0.6	1.32	1.08E−04	4.50E−06	7.00E−06	4.00E−07	1.079E−04
3	0.7	1.42	2.30E−04	9.60E−06	1.50E−05	9.00E−07	2.305E−04
4	0.8	1.53	4.42E−04	1.90E−05	2.90E−05	1.00E−06	4.433−04