fatigue oligocyclique

CONT: [Aciers] Les courbes donnant la durée de vie en fonction du nombre de cycles et de la contrainte cyclique, appelées courbes S - N, ont été établies dans un large domaine de contraintes, de nombres de cycles et de températures. La fatigue oligocyclique, qui est susceptible de se produire après un nombre de cycles limité lorsqu'il y a dépassement périodique de la limite d'élasticité du matériau, a, en particulier, fait l'objet de nombreux essais.

CONT: The behaviour of steel or composite joints under cyclic loading is characterized by hysteretic loops with progressive degradation of strength and stiffness that eventually leads to failure of the joint. A typical natural event that, for simplicity, is usually approximated by cyclic loading is an earthquake. Usually, seismic events provoke relatively high amplitudes of rotation in the joint area, so that steel repeatedly reaches the plastic range and the joint fails after a relatively small number of cycles. This typical behaviour is usually called oligocyclic fatigue, in close analogy with the behaviour of steel under repeated cyclic loading stressed into the plastic regime.