ISSN: 1945-7553
CODEN: JTEVAB
Page Count: 10

A Summary of Fracture Mechanics Concepts

Irwin, GR
ProfessorMembers of ASTM, University of Maryland, College Park, MD

de Wit, R
PhysicistMember of ASTM, Fracture and Deformation Division, Center for Materials Science, National Measurement Laboratory, National Bureau of Standards, Washington, DC,

Abstract

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.

Keywords:
fractures (materials), cracking (fracturing), modulus of elasticity, Charpy, corrosion, crack extension, fatigue, fracture mechanics, plasticity, strain, stress, toughness

Paper ID: JTE11586J
DOI: 10.1520/JTE11586J
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