Volume 11, Issue 1 (January 1983)
A Summary of Fracture Mechanics Concepts
The basic concepts of fracture mechanics are presented in a logical sequence. Each concept is given in a concise definition-like paragraph. The concepts of toughness, process zone, crack, and linear-elastic fracture mechanics are first introduced. The crack-tip characterizations, that is, stress-intensity factor, crack extension force, J integral, and crack-tip opening displacement are then discussed. The constraints in plane stress, plane strain, and three dimensions are pointed out. Various methods of evaluating the crack-tip characterizations are explained. The concept of fracture toughness is presented in relation to resistance curves, dynamics, constraints, and fast-stable crack growth. Some practical empirical fracture toughness relations are given. Then slow-stable crack growth is discussed, that is, stress corrosion cracking, fatigue cracking, corrosion fatigue, and viscous (creep) cracking. The summary concludes with the concept of fracture control plans.