Strong Cosserat Elasticity in a Transversely Isotropic Polymer Lattice

Z. Rueger, R. S. Lakes
2018 Physical Review Letters  
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 ¼ 9.4 mm; for bending, it is l b ¼ 8.8 mm; these values are comparable to
more » ... e cell size. Nonclassical effects are much stronger than in stretch-dominated lattices with uniform straight ribs. The lattice structure provides a path to the attainment of arbitrarily large effects.
doi:10.1103/physrevlett.120.065501 pmid:29481282 fatcat:asflwescxfegjfjpzc67pedouu