Damage failure, fracture, fatigue, creep

Some of the more important methods of failure studies include stress-strain, impact loading, and fatigue. Creep and stress relaxation (Chapter 10) may cause serious damage to engineering materials, but they normally do not result in fracture per se except for creep rupture. Emphasis in this chapter will be on the study of fracture energy, kinetics of crack growth, and molecular mechanisms. The reader is directed to Chapter 13 for a fuller discussion of plastic toughening. 

Each pipe forms a primary coolant pressure boundary and its failure in the form of a large leak or rupture is of great concern to safety. Hence, the structural reliability requirements are high for the component. With the view of this, detailed stress analysis has been carried out to optimize the thickness, and subsequently creep fatigue damage is estimated. Apart from postulating a pessimistic surface crack at a highly stressed location, fracture mechanics... 

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