Faceted fabrics

Rigid elements attached to floppy fabric

Part of a broader investigation into coupling rigid elements with compliant materials (see Beaded metamaterials, Haptic Lab), in this work I attach acrylic blocks to fabric. The elements are glued and so cannot freely slide or rotate. In a single row spanning two supports with facets oriented downwards, the shape is a classic catenary with no interaction between elements — like chain links (note that a beaded necklace takes a different shape). However, draping the strip in a scenario where bending in both directions is required causes elements to jam.

The result is some extremely anisotropic bending stiffness: in one direction the material is floppy or of negligible stiffness, and in the other direction, bending is forbidden, or jammed. This leads to unusual behaviors for fabrics, such as the ability to be both load-bearing and soft, atypical wrinkling patterns, and metastability.

Alternative limit case: stiff elements out-of-contact on an elastic sheet

In the previous examples, the substrate’s bending stiffness was negligible compared to the weight of the attached elements. Here, I consider the opposite limit: a substrate that resists bending. These sheets are designed so that the stiff elements do not touch, but instead interact through the elasticity of the sheet. In this configuration, jamming no longer occurs, but stiffness is spatially patterned. I am interested in how the lattice design affects the mechanical response, particularly in terms of dynamic vibrational modes.