Dihui Ruan1 Sylvain Patinet2 Christopher Rycroft3 Michael Shields1 Michael Falk1
1, Johns Hopkins University, Baltimore, Maryland, United States
2, Laboratoire PMMH,ESPCI, Paris, , France
3, Harvard University, Cambridge, Massachusetts, United States
Plastic deformation in metallic glasses and other amorphous solids is believed to be mediated by point defects referred to as shear transformation zones (STZs). STZs are defined as clusters of atoms rearranging cooperatively when strained plastically. However, locating STZs in the glass microstructure is a significant challenge. We deploy a local yield stress (LYS) method to evaluate the local stress at which instabilities are triggered in the microstructure of a simulated Cu64Zr36 metallic glass. We then use this data to locate STZs by finding the minima in this scalar field. The predictions of the LYS method are cross-correlated with molecular statics and molecular dynamics simulations of shear to verify the predictive nature of this nano-scale measure of material structure. We analyze the persistence of the LYS measure as well as the statistics of the defects identified.