VHCF ultrasonic tests on EN AW‐6082 aluminum alloy samples over a wide dimensional range

In the present paper, a very high cycle fatigue test campaign carried out with an ultrasonic testing machine up to 10^10 cycles is presented. The aluminum alloy hourglass and dog-bone samples have dimensions spanning over a very wide range, with the diameter in the middle cross-section comprised between 3 and 30 mm. From the experimental results, the influence of structural size can be clearly detected, and it is possible to observe a transition between small scales, where the size effect is more pronounced, and larger scales, where the size effect is vanishing. This phenomenon can be explained in an effective way by adopting a multifractal formalism, which is equipped with the probabilistic treatment of the statistical dispersion of experimental data.