title: Curvature condensation and bifurcation in an elastic shell.
abstract: We study the formation and evolution of localized geometrical defects in an indented cylindrical elastic shell using a combination of experiment and numerical simulation. We find that as a symmetric localized indentation on a semicylindrical shell increases, there is a transition from a global mode of deformation to a localized one which leads to the condensation of curvature along a symmetric parabolic defect. This process introduces a soft mode in the system, converting a load-bearing structure into a hinged, kinematic mechanism. Further indentation leads to twinning wherein the parabolic defect bifurcates into two defects that move apart on either side of the line of symmetry. A qualitative theory captures the main features of the phenomena but leads to further questions about the mechanism of defect nucleation.
authors.affiliation: Division of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA.
authors.forename: Moumita
authors.initials: M
authors.lastname: Das
authors.forename: Ashkan
authors.initials: A
authors.lastname: Vaziri
authors.forename: Arshad
authors.initials: A
authors.lastname: Kudrolli
authors.forename: L
authors.initials: L
authors.lastname: Mahadevan