What is the force needed to crush a soda can? Under what loading is a rocket shell guaranteed to never collapse? Surprisingly, there is no great answer to these seemingly basic questions. The predictions based on linear stability analyses strongly overestimate the critical loads observed in the experiments over the last 50 years. In real systems, defects weaken these thin-walled cylinders and cause them to collapse prematurely. As a result, it is quite difficult to guarantee their stability.

15 Second Summary: We are interested in the material properties that govern the scale, extent and morphology of hydraulic fractures in brittle materials.  Our goal is to study fluid driven crack propagation in a variety of brittle hydrogels, where the time scale of these fractures is slow enough that we can study the dynamics of the fracture as well.

Friction is everywhere – it keeps your car on the road, your coffee cup in your hand, and your feet beneath you. If you took physics in high school, it’s likely you know about static (non-moving) and kinetic (moving) friction. Static friction is stronger than kinetic friction, both resist movement and are constant regardless of time elapsed or speed of sliding. This model, the one most commonly known, is called Amonton-Coulomb Friction, and it is anything but the full picture. 

Aging of Frictional Interfaces