78307.fig.005
Figure 5: Type of nonlinearity for mode (0,2) with an axisymmetric imperfection having the shape of mode (0,1). 2:1 internal resonances with modes (0,3), (0,4), and (0,5) occurs, respectively, for 𝜃 = 0 = 1.74, 5.43, and 9.92.