Strong Cosserat Elasticity in a Transversely Isotropic Polymer Lattice.

@article{Rueger2018StrongCE,
  title={Strong Cosserat Elasticity in a Transversely Isotropic Polymer Lattice.},
  author={Zach Rueger and Roderic S. Lakes},
  journal={Physical review letters},
  year={2018},
  volume={120 6},
  pages={
          065501
        }
}
Large size effects are experimentally measured in lattices of triangular unit cells: about a factor of 36 in torsion rigidity and 29 in bending rigidity. This nonclassical phenomenon is consistent with Cosserat elasticity, which allows for the rotation of points and distributed moments in addition to the translation of points and force stress of classical elasticity. The Cosserat characteristic length for torsion is ℓ_{t}=9.4  mm; for bending, it is ℓ_{b}=8.8  mm; these values are comparable to… 
View on PubMed
link.aps.org
55 Citations
Highly Influential Citations
2
Background Citations
17
Methods Citations
5
Results Citations
2

Figures from this paper

55 Citations

Cosserat elastic lattices

AbstractLattices composed of cubic and triangular prismatic unit cells with polymeric Sarrus linkage rib elements are designed, fabricated via 3D printing and studied experimentally. Size effects in…

Cosserat elastic lattices

Lattices composed of cubic and triangular prismatic unit cells with polymeric Sarrus linkage rib elements are designed, fabricated via 3D printing and studied experimentally. Size effects in these…

Flexible Cube Tilt Lattice with Anisotropic Cosserat Effects and Negative Poisson's Ratio

A 3D lattice structure consisting of pivoting cubes with flexible links at the corners is presented. It exhibits anisotropic negative Poisson's ratio −0.54 and −0.75. Size effects occur in torsion…

Experimental Study of Elastic Constants of a Dense Foam with Weak Cosserat Coupling

A dense closed cell foam is studied to determine which continuum theory of elasticity is applicable. Size effects inconsistent with classical elasticity are observed. The material exhibits a…

Experimental evaluation of micromorphic elastic constants in foams and lattices

  • R. Lakes
  • Engineering
    Zeitschrift für angewandte Mathematik und Physik
  • 2022
Micromorphic (microstructure) elastic constants are considered within the context of experimental results for foams and rib lattices and of subsets such as Cosserat elasticity, void elasticity and…

Odd Cosserat elasticity in active materials

Stress-strain constitutive relations in solids with an internal angular degree of freedom can be modelled using Cosserat (also called micropolar) elasticity. In this paper, we explore the…

Nonclassical Chiral Elasticity of the Gyroid Lattice.

The gyroid lattices were made in chiral and nonchiral form by 3D printing and exhibited nonclassical elastic effects including coupling between compressive stress and torsional deformation.

Micropolar modeling of a typical bending-dominant lattice comprising zigzag beams

Unexpected bending behavior of 2D lattice materials

Architected 2D lattice materials are appealing for shape-shifting applications due to the tunable sign of Poisson’s ratio. It is commonly believed that the positive and negative Poisson’s ratios lead…

Extremal hinged lattices do not obey the theory of elasticity

  • R. Lakes
  • Engineering
    Zeitschrift für angewandte Mathematik und Physik
  • 2021
Hinged lattices that attain extremal values of Poisson’s ratio do not in general obey the theory of elasticity. Hinged structures that attain a Poisson’s ratio of − 1 are easy to stretch or deform…
...

References

SHOWING 1-10 OF 31 REFERENCES

Experimental Cosserat elasticity in open-cell polymer foam

Reticulated open-cell polymer foams exhibit substantial size effects in torsion and bending: slender specimens are more rigid than anticipated via classical elasticity. Such size effects are…

Elasto-static micropolar behavior of a chiral auxetic lattice

Cosserat elasticity of negative Poisson’s ratio foam: experiment

Negative Poisson’s ratio polymer foams derived from reticulated open cell foams exhibit large size effects in torsion and bending. Effective moduli increase as diameter decreases in contrast to the…

Untwisting of a cholesteric elastomer by a mechanical field

A mechanical strain field applied to a monodomain cholesteric elastomer will unwind the helical director distribution via the elimination of sharp, pinned twist walls above a critical strain.

Length scales at which classical elasticity breaks down for various materials.

Using a combination of empirical molecular dynamics and lattice dynamics, this work provides estimates of nonlocal elasticity length scales for various classes of materials: semiconductors, metals, amorphous solids, and polymers.

A structural model of a micropolar continuum

Experimental evidence of rotational elastic waves in granular phononic crystals.

The experimental observation of coupled rotational-translational modes in a noncohesive granular phononic crystal is reported, showing that the Cosserat theory fails to predict correctly the dispersion of the elastic modes in granular crystals even in the long-wavelength limit.

Size effects due to Cosserat elasticity and surface damage in closed-cell polymethacrylimide foam

This article describes the experimental investigation of Cosserat (or micropolar) elasticity and surface damage effects in closed-cell polymethacrylimide foams of different densities. The method of…

Analytical Derivation of Cosserat Moduli via Homogenization of Heterogeneous Elastic Materials

Why do experiments detect Cosserat-elastic effects for porous, but not for stiff-particlereinforced, materials? Does homogenization of a heterogeneous Cauchy-elastic material lead to micropolar…

Unusual flexoelectric effect in two-dimensional noncentrosymmetric sp2-bonded crystals.

It is found that the single-atom-thick sp2-bonded noncentrosymmetric crystals like boron-nitride (BN) sheet exhibit an unusual nonlinear electromechanical effect: they become strongly macroscopically polarized in a corrugated state.