Abstract

Shapeability is commonly found in inelastic networks, for example --- a sheet of paper. When crumpled, a sheet of paper retains some amount of shapability that a bare, uncrumpled paper does not have: if deformed by external forces, it retains the deformed shape even after the forces are removed.

Our numerical investigations show that a simpler system - just a 2D network of elastic springs, has the same behavior. The elastic network contains an extensive number of bistable energy minima, suggesting plasticity is not mandatory for shapeability. A strictly elastic network with bistable points can store a range of structural configurations and exhibit properties traditionally attributed to plasticity such as hysteresis and memory storage. 

The numerical sheet can be bent into a nearly-closed cylinder that holds its shape.  We verify that the deformed shape is locally stable and investigate the threshold for non-elastic deformation.