Buckling of spontaneously twisted ribbons

We study the effect of spontaneous twist on the buckling instability of thin rectilinear elastic filaments with non-circular cross-section (ribbons). We find that the presence of twist in the stress-free reference state increases, albeit non-monotonically, the critical load at which buckling takes place. Stability with respect to buckling increases with the asymmetry of the cross-section and saturates at twice the Euler value for an untwisted beam. The classical Euler result is recovered, independent of twist, for filaments with circularly symmetric cross-section.