Résumé:
This master's thesis is a comparative study, by the first approach called strength of of
materials, based on the simulation of the three and four points bending of a beam without cracks
by the finite element software RDM6, developed by the Le MANS university of France ; and
by the second approach called fracture mechanics of the two previous stresses, by simulation
of the three and four point bending of the same beam at fracture, by the fracture analysis code
Franc2D (in English fracture analysis code 2 dimensions ), developed by Cornell Fracture
Group, and Cornell University, of United States of America (USA), for the determination of
the stress intensity factors KI for different distances from the middle em of the beam to be
studied, which led us to calculate the critical crack lengths aC for each case of the previous
removals.