Fig. 8.

Time average of the writhing number 〈Wr〉 (left) and RMS amplitudes (right) of the first clamped twisting mode for η = 0.1 as functions of the imposed torsional moment Û⁰. In the RMS amplitudes plot, the solid black line represents the out-of-plane RMS amplitude $({\mathrm{\alpha ̃}}_n^{\mathrm{R}\mathrm{M}\mathrm{S}})$, the dashed black line the in-plane RMS amplitude $({\mathrm{\beta ̃}}_n^{\mathrm{R}\mathrm{M}\mathrm{S}})$ and the mixed dashed black line the twisting RMS amplitude $({\mathrm{\delta ̃}}_n^{\mathrm{R}\mathrm{M}\mathrm{S}})$.