method

M_a = 2

Flutter parameter

β

ω_1st

ω_2nd

ω_f

M_af

error

Galerkin’s third-order

64.02

650.73

2130.32

1773.44

7.18

2.69%

Exact soultion

64.01

651.97

2130.66

1759.93

6.99