Experimental study of crease formation in an axially compressed sheet

In our study of crease formation in a cylindrical panel subject to axial compression, we found that the maximum vertical deflection ζ increases in the orthoradial direction l and saturates when the panel is larger than half a cylinder. The length of the crease X decreases by increasing the panel opening angle, and saturates to a constant value when the opening angle is close to 2π. The stress corresponding to initial crease formation goes as $1/R$, where R is the radius of curvature of the panel. Profilometric measurements reveal the presence of a region around the singularity where the stress is focused and where the deformation is plastic.