On the use of the Prismatic Hull method in a critical plane-based multiaxial fatigue criterion

• Modified Carpinteri-Spagnoli C-S criterion is combined with Prismatic Hull PH method.
• The equivalent shear stress amplitude on the critical plane computed by the PH method.
• The PH method is formulated both for synchronous and asynchronous loading.
• Experimental data available in literature are compared with theoretical estimations.
• The PH method produces less non-conservative results than those by the MCC method.

In the present paper, the modified Carpinteri–Spagnoli (C–S) criterion is combined with the Prismatic Hull (PH) method proposed by Mamiya, Araújo et al. [15] to evaluate an equivalent shear stress amplitude for multiaxial fatigue loading. More precisely, the PH method, originally formulated for synchronous loading and successively extended to asynchronous loading, is here adopted to compute the shear stress amplitude acting on the critical plane, used in the modified C–S criterion. By comparing some experimental data available in the literature with the theoretical estimations, the multiaxial fatigue strength evaluations derived through the modified C–S criterion are shown to be improved if the shear stress amplitude is determined by applying the PH method instead of the Minimum Circumscribed Circle (MCC) method, especially for particular shear stress paths as is here discussed.