  The mechanical properties of thermally excited two-dimensional crystalline
membranes can depend dramatically on their geometry and topology. A
particularly relevant example is the effect on the crumpling transition of
holes in the membrane. Here we use molecular dynamics simulations to study the
case of elastic frames (sheets with a single large hole in the center) and find
that the system approaches the crumpled phase through a sequence of
origami-like folds at decreasing length scales when temperature is increased.
We use normal-normal correlation functions to quantify the
temperature-dependent number of folds.
