Elastogranular columns and beams
Arman Guerra1, Casey Lautzenhiser1, Xin Jiang1
1Mechanical Engineering, Boston University, Boston, MA, 02215, USA. dpholmes@bu.edu.
Abstract:
String and grains can be combined to create structures capable of bearing significant loads. In this work, we prepare columns and beams through a layer-by-layer deposition of granular matter and loops of fiber strings, and characterize their mechanical properties. The loops cause the grains to jam, and the inter-grain contact leads to a Hertzian-like constitutive response. Initially, one force chain that propagates vertically through the column bears most of the compressive load. As the magnitude of the load is increased, more force chains form in the column, which act in parallel to increase its stiffness, akin to a "super-Hertzian" regime. Applying a compressive prestress enables the structures to withstand shear, enabling the fabrication of cantilevered beams. This work provides a mechanical framework to use elastogranular jamming to create rapid, reusable infrastructure components, such as columns, beams, and arches from inexpensive, commonplace materials, such as rocks and string.
Related Concept Videos
Design of Columns under a Centric Load
Euler's formula is applicable under the assumption that the column is a perfect, straight, homogenous prism, and it is operating...
Design of Columns under an Eccentric Load
Euler's Formula to Columns with Other End Conditions
Design of Prismatic Beams for Bending
Beams
Based on geometry, beams can be straight, tapered, or curved. Straight beams are the most common type and have a constant cross-section throughout their length. Tapered beams, on the other hand, have a varying cross-section along...
Members Made of Elastoplastic Material
As the bending moment...


