title: Crescent singularities in crumpled sheets.
abstract: We examine the crescent singularity of a developable cone in a setting similar to that studied by Cerda et al., [Nature (London) 401, 46 (1999)]. Stretching is localized in a core region near the pushing tip and bending dominates the outer region. Two types of stresses in the outer region are identified and shown to scale differently with the distance to the tip. Energies of the d cone are estimated and the conditions for the scaling of core region size Rc are discussed. Tests of the pushing force equation and direct geometrical measurements provide numerical evidence that core size scales as Rc approximately h(1/3)R(2/3), where h is the thickness of sheet and R is the supporting container radius, in agreement with the proposition of Cerda et al. We give arguments that this observed scaling law should not represent the asymptotic behavior. Other properties are also studied and tested numerically, consistent with our analysis.
authors.affiliation: The James Franck Institute, Department of Physics, The University of Chicago, 5640 S. Ellis Avenue, Chicago, Illinois 60637, USA.
authors.forename: Tao
authors.initials: T
authors.lastname: Liang
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Witten