Investigation on parametric representation of proportional and nonproportional multiaxial fatigue responses

Abstract

ABSTRACT. This study aims to investigate fatigue damage resulting from multiaxial fatigue, proportional and/or nonproportional, loading by analyzing stresses and strains over a full domain around a representative stress-strain element. Plain stress-strain transformation of multiaxial hysteresis was performed by varying orientation of plane for 0≤φ≤2π. Parametric representations for both normal and shear stresses and strains were obtained by plotting them in polar figures. These figures show that depending on the applied loading stresses and strains represent definitive known parametric curves. Parametric representation of fatigue damage parameter such as Fatemi-Socie suggests that fatigue damage shall be calculated as the sum of the damage values on all planes. The proposed technique has been shown to improve fatigue life prediction compared to that obtained from the critical plane method.

40CrMoV13.9 notched specimens under multiaxial fatigue: an overview of recent results

“…This makes it especially important to be able to accurately estimate fatigue damage under multiaxial loading. To this end, considerable effort in the past decades has been put into developing damage parameters which reflect the actual damage mechanisms of the multiaxial fatigue failure process [1][2][3][4][5][6]. Numerous predictive methods have been proposed in the literature for the cracked and notched components under multiaxial loading including the critical plane [7,8], energetic criterion [9] and thermodynamics based method [10].…”