Cosserat shape effects in the bending of foams

Abstract

In classical pure bending of a bar of square cross sections, two lateral surfaces undergo anticlastic curvature and the other two lateral surfaces undergo tilt. If the bar is made of a Cosserat solid, the tilted lateral surfaces deform in a sigmoid shape in addition to tilt. Parametric studies reveal the bulge depends on the bending characteristic length, the coupling number, and the ratio of two Cosserat rotation gradient constants. This sigmoid bulge deformation is observed in two foams and is found to be consistent with predictions using elastic constants obtained from size effect studies.

Keywords:

• Cosserat
• micropolar
• bending
• foams
• generalized continuum

Acknowledgment

We gratefully acknowledge support by the National Science Foundation via Grant No. CMMI-1906890.