Project acronym FRACTFRICT
Project Fracture and Friction: Rapid Dynamics of Material Failure
Researcher (PI) Jay Fineberg
Host Institution (HI) THE HEBREW UNIVERSITY OF JERUSALEM
Call Details Advanced Grant (AdG), PE3, ERC-2010-AdG_20100224
Summary FractFrict is a comprehensive study of the space-time dynamics that lead to the failure of both bulk materials and frictionally bound interfaces. In these systems, failure is precipitated by rapidly moving singular fields at the tips of propagating cracks or crack-like fronts that cause material damage at microscopic scales. These generate damage that is macroscopically reflected as characteristic large-scale, modes of material failure. Thus, the structure of the fields that microscopically drive failure is critically important for an overall understanding of how macroscopic failure occurs.
The innovative real-time measurements proposed here will provide fundamental understanding of the form of the singular fields, their modes of regularization and their relation to the resultant macroscopic modes of failure. Encompassing different classes of bulk materials and material interfaces.
We aim to:
[1] To establish a fundamental understanding of the dynamics of the near-tip singular fields, their regularization modes and how they couple to the macroscopic dynamics in both frictional motion and fracture.
[2] To determine the types of singular failure processes in different classes of materials and interfaces (e.g. the brittle to ductile transition in amorphous materials, the role of fast fracture processes in frictional motion).
[3] To establish local (microscopic) laws of friction/failure and how they evolve into their macroscopic counterparts
[4]. To identify the existence and origins of crack instabilities in bulk and interface failure
The insights obtained in this research will enable us to manipulate and/or predict material failure modes. The results of this study will shed considerable new light on fundamental open questions in fields as diverse as material design, tribology and geophysics.
Summary
FractFrict is a comprehensive study of the space-time dynamics that lead to the failure of both bulk materials and frictionally bound interfaces. In these systems, failure is precipitated by rapidly moving singular fields at the tips of propagating cracks or crack-like fronts that cause material damage at microscopic scales. These generate damage that is macroscopically reflected as characteristic large-scale, modes of material failure. Thus, the structure of the fields that microscopically drive failure is critically important for an overall understanding of how macroscopic failure occurs.
The innovative real-time measurements proposed here will provide fundamental understanding of the form of the singular fields, their modes of regularization and their relation to the resultant macroscopic modes of failure. Encompassing different classes of bulk materials and material interfaces.
We aim to:
[1] To establish a fundamental understanding of the dynamics of the near-tip singular fields, their regularization modes and how they couple to the macroscopic dynamics in both frictional motion and fracture.
[2] To determine the types of singular failure processes in different classes of materials and interfaces (e.g. the brittle to ductile transition in amorphous materials, the role of fast fracture processes in frictional motion).
[3] To establish local (microscopic) laws of friction/failure and how they evolve into their macroscopic counterparts
[4]. To identify the existence and origins of crack instabilities in bulk and interface failure
The insights obtained in this research will enable us to manipulate and/or predict material failure modes. The results of this study will shed considerable new light on fundamental open questions in fields as diverse as material design, tribology and geophysics.
Max ERC Funding
2 265 399 €
Duration
Start date: 2010-12-01, End date: 2016-11-30
Project acronym STANPAS
Project Statistical and Nonlinear Physics of Amorphous Solids
Researcher (PI) Itamar Procaccia
Host Institution (HI) WEIZMANN INSTITUTE OF SCIENCE
Call Details Advanced Grant (AdG), PE3, ERC-2010-AdG_20100224
Summary I propose an extensive and ambitious program to greatly increase our understanding of the properties of amorphous solids, focusing mainly on the mechanical and magnetic properties of these fascinating materials, including their modes of failure via plastic flow, shear banding and fracture. Amorphous solids are important in many modern engineering applications, including as important examples structural glasses, metallic glasses and polymeric glasses. Our work combines a careful analysis of computer simulations of model-glasses with analytic theory in which we introduce to material science methods from statistical and nonlinear physics, both of which are subjects of expertise in our group. We challenge some present approaches that try to connect linear elasticity with some objects that carry plasticity; we claim that nonlinear elasticity is crucial, as its signature appears much before plastic failure. Similarly, we break away from current theories that assume that plastic events are spatially localized. We show that in athermal conditions the opposite is true, and we discover very interesting sub-extensive scaling phenomena characterized by a host of scaling exponents that need to be understood. The peculiarities of amorphous solids, in particular their memory of past deformation, call for the identification of new 'order parameters' that are sorely missing in present theories. Understanding the dependence on system size, temperature, external loading rates etc. calls for introducing new approaches and methods from statistical and nonlinear physics. In the body of the proposal we present a number of preliminary results that point towards a radically new way of thinking that we propose to develop to a new theory over the next five years.
Summary
I propose an extensive and ambitious program to greatly increase our understanding of the properties of amorphous solids, focusing mainly on the mechanical and magnetic properties of these fascinating materials, including their modes of failure via plastic flow, shear banding and fracture. Amorphous solids are important in many modern engineering applications, including as important examples structural glasses, metallic glasses and polymeric glasses. Our work combines a careful analysis of computer simulations of model-glasses with analytic theory in which we introduce to material science methods from statistical and nonlinear physics, both of which are subjects of expertise in our group. We challenge some present approaches that try to connect linear elasticity with some objects that carry plasticity; we claim that nonlinear elasticity is crucial, as its signature appears much before plastic failure. Similarly, we break away from current theories that assume that plastic events are spatially localized. We show that in athermal conditions the opposite is true, and we discover very interesting sub-extensive scaling phenomena characterized by a host of scaling exponents that need to be understood. The peculiarities of amorphous solids, in particular their memory of past deformation, call for the identification of new 'order parameters' that are sorely missing in present theories. Understanding the dependence on system size, temperature, external loading rates etc. calls for introducing new approaches and methods from statistical and nonlinear physics. In the body of the proposal we present a number of preliminary results that point towards a radically new way of thinking that we propose to develop to a new theory over the next five years.
Max ERC Funding
1 792 858 €
Duration
Start date: 2011-04-01, End date: 2016-03-31
