Fracture Mechanics: Atomistic Cohesive Zone Law

This lecture delves into the concept of fracture mechanics, focusing on crack-tip energy dissipation, cohesive zone modeling, and crack growth behavior under varying stress levels. The instructor explains the role of dissipative processes, plastic deformation, and fiber bridging in energy dissipation during crack propagation. The cohesive zone concept is introduced to describe the tractions exerted on the crack, and the lecture explores the problem-solving approach for crack opening and applied stress. Atomistic scale fracture behavior is analyzed, highlighting the cohesive zone's association with surface energy. The Atomistic Cohesive Zone Law is discussed, emphasizing the procedure for determining surface stress, computing virial stress, and measuring tractions along the crack plane. The lecture concludes with insights on maximum toughening and the total work done in pulling apart material during crack growth.