Soft coring : how to get a clarinet out of a flute ? Extreme Mechanics Letters, 2023

Lechenault F., Ramdane I., Moulinet S., Roman-Faure M. and Ciccotti M., 2023. Soft coring : how to get a clarinet out of a flute ?. Extreme Mechanics Letters, 61, 101976.

Cutting mozzarella with a dull blade results in poorly shaped slices : the process occurs in a configuration so deformed as to yield unexpectedly curved surfaces. We study the morphogenetics arising from such process through the example of coring : when a thin cylindrical hollow punch is pushed into a soft elastomer, the large transverse expansion occurring during the cutting is responsible for the “clarinet-shape” of the extracted core, which reaches diameters far smaller than those of the tool. With contributions from fracture mechanics and large strain theory, we build a simple yet quantitative understanding of the observed discrepancy, which is shown to occur when the size of the punch is smaller than a characteristic, tomo-elastic length scale. Moreover, material nonlinearity and friction appear to play a crucial role in this phenomenon.