Crack growth path of 30CrMnSiA steel under variable amplitude multiaxial loading

Two-level step multiaxial fatigue tests were conducted to investigate the crack growth behavior and damage accumulation of 30CrMnSiA steel. When the first load step (50% of the fatigue failure life) is completed, main cracks of specimens have entered the stage II propagation. The cracks gradually turn direction to propagate along the maximum normal stress planes of load step 2 under the second load step. The damage accumulation is mainly affected by the angle between the maximum normal stress planes of the two-level step loadings and the crack propagation length along the depth direction, it will also lead to large error of fatigue life prediction by the commonly used damage accumulation models.

Automated summary

Two-level step multiaxial fatigue tests on 30CrMnSiA steel revealed that crack growth behavior is influenced by the maximum normal stress planes, and the crack propagation length along the depth direction affects damage accumulation.