By redistributing stresses, curvature provides a
geometric tool for controlling how materials fracture. In particular, curvature
can guide where fracture initiates and how it evolves. At the Chicago MRSEC, Irvine
and MRSEC international collaborator Vitelli from the University of Leiden
demonstrate this using thin elastic sheets confined to geometries with positive
(shown in red in the images) and negative (blue) Gaussian curvature.
The team’s experiments and simulations show, for the
first time, how curvature can be used to stimulate or suppress the growth of
cracks, and steer or arrest their propagation. Since stresses from curvature
are independent of material parameters, the results have general implications
and open up new opportunities for fracture control from the nanoscale to
geological strata.