Abstract: Tape a stiff wire to a sheet of paper. Then bend the wire up and down, out of the paper plane. The paper must follow these bends near the wire. Remarkably, the wire also dictates the shape indefinitely far on either side, as shown in the photo. This long- range response to forcing happened because the paper is thin, and thus acts as though it were unstretchable.  Any departure from the curvature dictated by the wire would cause stretching and is thus strongly suppressed. If we had taped two wires, their dictates would in general conflict, creating frustration.  This talk explores  newly-recognized   forms   generated   by   this frustration.  The frustration creates focussing of elastic energy into well-defined shapes that constrain the form of whole sheet. We'll consider three cases: a curved crease in an infinite sheet. faceted ruffling caused by pulling inward on a curved boundary, and inserting an extra wedge of material into an already curved
sheet.

In-Person Location:  Bldg. 440, A105/A106

Virtual Link: https://argonne.zoomgov.com/j/1600052763