The interrelation between statistical distributions of the cyclic lifetime and dynamic fracture toughness with fracture mechanisms

摘要

The interrelation between statistical distributions of the cyclic lifetime and dynamic fracture toughness with fracture mechanisms has been reported. The necessity to establish such interrelation is caused by the circumstance that, as the cyclic lifetime or fracture toughness varies, the linearity of probabilistic curves is violated, and evaluation of the probability of the fracture is complicated. Other researchers used the weight coefficients to evaluate the probability, which allowed them to take into account two different mechanisms of fracture. This leads to decrease the correlation coefficients that characterize the exactness of the description of the experimental data. Thus, the performed analysis described the probabilistic curves obtained under cyclic and impact loading by simple exponential relations, the indexes of which characterize the form of probabilistic curves and are associated with the parameters determining the fracture mechanism, namely, the amplitude of cyclic loading and the testing temperature under the conditions of impact loading.