	Coupled-mode Zero-frequency mode or static divergence			Buckling
Before flutter	β ≤ 0, ω > 0	β ≤ 0, ω > 0	β ≤ 0, ω > 0
Flutter state	β₁ = β₂ = 0, ω₁ = ω₂ > 0 β_i < 0, ω_i > 0, i > 2	β₁ = β₂ = 0, ω₁ = ω₂ > 0 β_i < 0, ω_i > 0, i > 2	β₁ = 0, β_i_¹₁ < 0 ω₁ = 0, ω_i_¹₁ > 0
After flutter	β₁ = β₂ > 0, ω₁ = ω₂ > 0 β_i < 0, ω_i > 0, i > 2	β₁ = β₂ > 0, ω₁ = ω₂ > 0 β_i < 0, ω_i > 0, i > 2	β₁ > 0, β_i_¹₁ < 0 ω₁ = 0, ω_i_¹₁ > 0
Frequency	M_a? ω₁? ω _i_¹₁?	M_a? ω₁? ω _i_¹₁?then?	M_a? ω?	whenM_a a _cr N_x? ω?
M_a	M_a_cr ≤ M_a_f	M_a_cr ≤ M_a_f	M_a_cr = M_a_f
Boundary conditions	SS, CC, FF, GG, SC	CF,SF,GF,CG,SG	GC, GS	SS, CC, FF, GG, SC, SF, CF, GF, GC, GS