Cutting and tearing thin elastic sheets: two novel single-period cracks and the first period-doubling crack

TL;DR

This paper reports novel crack patterns in thin elastic sheets, including single-period and period-doubling cracks, influenced by anisotropy and contact conditions, with distinct growth dynamics observed.

Contribution

It introduces new crack types in thin sheets and links their formation to anisotropy and contact mechanics, providing insights into crack propagation behaviors.

Findings

Discovered two novel single-period cracks in experiments.

Observed a period-doubling crack linked to contact region changes.

Crack growth during cutting follows a logistic (S-curve), tearing cracks follow a power-law.

Abstract

Two novel single-period cracks were observed in experiments of cutting a folded sheet with a blunt object and tearing a thin brittle sheet under the guidance of a meterstick. Additionally, we observed a period-doubling crack in the tearing experiment. We cut and tore the sheet in different directions. The experimental results suggested that the anisotropy of the thin sheet played an important role in the formation of these two types of saw-tooth cracks. We demonstrated that the formation of the period-doubling crack was closely correlated with the changing of the contact region between the sheet and the meterstick. We also showed that the growth process of crack made by cutting was a logistic growth process (S-curve), while the cracks made by tearing propagated in the form of approximate power-law function.