Dr. Shahar Gvirtzman

Shahar Gvirtzman did his doctoral research at Hebrew University of Jerusalem’s Physics Department, where he conducted novel friction experiments. He studied the moments when two contacting bodies under both normal and shear stress suddenly start to slide against one another. When these two bodies are tectonic plates, this sudden initiation is an earthquake. Scientists have largely understood the latter part of this process, in which fast rupture fronts propagate along the frictional interface and enable sliding to begin. Dr. Gvirtzman researched the initial stage of this process, called nucleation, in which the initial rupture is formed by an elusive and unknown procedure.

Dr. Gvirtzman obtained, for the first time, detailed lab measurements of rupture nucleation, and described its unique characteristics. Together with his colleagues, he showed that the existing theoretical framework for dynamic rupture, Fracture Mechanics, can be extended to include the nucleation stage by accounting for the geometry of the nucleation patch and the finite thickness of the frictional interface. These experimental and theoretical results provide a better understanding of the onset of frictional motion in general, and of earthquake initiation dynamics specifically.

For his postdoctoral research at MIT’s Civil and Environmental Engineering Department, Dr. Gvirtzman moves from investigating fracture at the interface between two materials, to investigating fracture dynamics at the bulk of a material. He inflates a cavity within a transparent material and tracks the entire expansion process, including the transition to fracture.
Specifically, he researches fracture in soft materials, trying to understand how fracture dynamics depend on a material’s softness.
Gaining a better understanding of 3D fracture is important from a fundamental science approach, and has important applications in the field of material integrity and stability.