Abstract
The response of a homeotropically aligned columnar phasmidic liquid crystal (CPLC) to rectilinear oscillatory shear was investigated for frequencies between 10(-2) and 100 Hz and cell thicknesses between 20 and 100 mum. At threshold shear amplitude, we observed a spatial pattern consisting of stationary bands, perpendicular to the direction of shear and localized in the bulk of the columnar sample. For fixed thickness and at threshold shear amplitude, we observed band structure for several frequencies corresponding to integer harmonics v(o), 2v(o), 3v(o). We interpret the obtained results in terms of curvature walls that evolve gradually, according to the amplitude, to characteristic developable domain walls of the columnar phase.