The course intends to provide the fundamental concepts of Linear Elastic Fracture Mechanics. After introducing the pioneering energy approach by A.A.Griffith (1920), the stress intensification concept is widely discussed, presenting the two fundamental mathematical approaches to solve the singular stress field in the crack tip vicinity:
- (i) the complex potential method by Westergaard (1939), and
- (ii) the series expansion method by Williams (1952).
With the latter, it is possible to study also the stress intensification at the vertex of re-entrant corners. Then, the fundamental relationship between the energy and the stress- ntensity approaches is illustrated according to the original demonstration due to G.R.Irwin (1957). The stress-intensity fracture criterion is also generalized to Mixed Mode conditions. In addition, the size of the plastic zone at the crack tip is evaluated, according to the different approaches by Irwin and Dugdale (1960).
Finally, the brittleness number is defined as a function of yield strength, fracture toughness and structural size-scale