Alternating color stripes flanking the ridge are caused by the vanishing of first stretching energy, then bending energy as one moves away from the ridge. Faint induced ridges extend from each vertex and meet at the edges at front and back. Similar ridge structures occur when a sheet or membrane is crumpled. Energy distribution in a thin, flat, sheet of elastic material, cut and joined to form a tetrahedron, showing ridge singularities. Distance between vertices is 1581 times the thickness.
Color indicates ratio of stretching to bending energy.
Near the vertices, bending energy is more than ten times stretching energy. In the middle of the ridge bending energy is 2.95 times stretching energy. Brightness indicates total energy density. Alternating color stripes flanking the ridges are caused by the vanishing of first stretching, then bending energy as one moves away from the ridge. Similar ridge structures occur when a sheet or membrane is crumpled.