Fracture Mechanics is a technology used for the assessment of the load bearing capacity of structures containing crack-like defects. The technology is based on the use of fracture parameters, K for linear elastic deformation behavior and J or CTOD for non-linear deformation behavior. These fracture parameters are used for the evaluation of Fracture behavior under monotonic loading, labeled fracture toughness, cracking under cyclic loading, fatigue crack growth, and for environmentally assisted cracking. The fracture mechanics approach can be used for the development of design criteria as well as material selection and failure analysis. In this lecture some of the basic parameters used in a fracture mechanics assessment will be discussed as well as some of the history and people involved in the development of the fracture mechanics approaches. This lecture will concentrate on the basis of fracture parameters and their use in the development of fracture testing methods and procedures.
Methods and examples of structural integrity assessment based on fracture mechanics parameters will be presented. First, the linear elastic (K I vs. K Ic ) problem will be analysed, then elastic-plastic, using parameters such as J integral and CTOD, and methods such as CTOD design curves, Failure Analysis Diagram (FAD), Crack Driving Force (CDF) vs. J-R curves, EPRI procedure. Numerical examples will be presented for most of the methods explained.