Geometry and Physics of tearing

What is the shape of the remaining pieces when we tear a piece of paper? Can we control the fracture path ?

These simple questions are in fact challenging for fracture mechanics (i will explain why).

Yet experiments show that the crack path are in fact very reproducible (when using a good material).

In this seminar i will try to show that paths can be predicted with very simple arguments

and illustrate this with several examples. Finally i will try to answer burning questions such as :

What is the best way to peel off adhesive tape ? What is the best way to cut a piece of paper with a ruler ?

Part of the NSCS webinar series https://softmatterisrael.wixsite.com/nscs