Evolution of Maximum Bending Strain on Poisson's Ratio Distribution

TL;DR

This paper investigates how the maximum bending strain (MBS) varies with Poisson's ratio distribution, revealing that nonuniform Poisson's ratio can enhance flexibility and MBS in thick nanofiber membranes.

Contribution

It introduces the concept that nonuniform Poisson's ratio distribution can be used to improve MBS and flexibility in thick materials, challenging traditional uniform assumptions.

Findings

MBS is only universal for materials with uniform Poisson's ratio.

MBS increases with thickness when Poisson's ratio varies.

Nonuniform Poisson's ratio in nanofiber membranes enables larger MBS and lower Young's modulus.

Abstract

In recent years, new flexible functional materials have attracted increasing interest, but there is a lack of the designing mechanisms of flexibility design with superstructures. In traditional engineering mechanics, the maximum bending strain (MBS) was considered universal for describing the bendable properties of a given material, leading to the universal designing method of lowering the dimension such as thin membranes designed flexible functional materials.In this work, the MBS was found only applicable for materials with uniformly distributed Poisson's ratio, while the MBS increases with the thickness of the given material in case there is a variation Poisson's ratio in different areas. This means the MBS can be enhanced by certain Poisson's ratio design in the future to achieve better flexibility of thick materials. Here, the inorganic freestanding nanofiber membranes, which have a nonconstant Poisson's ratio response on stress/strain for creating nonuniformly distributed Poisson's ratio were proven applicable for designing larger MBS and lower Young's modulus for thicker samples.