Author : Fathi Abdul Sahib Alshamma and Mohammed Abdul Gani Gali

In this paper, a theoretical and experimental study of the behavior of metals under multiaxial fatigue by combination of cycling bending with torsion for non-proportional loading. In the theoretical analysis, Mohr circle have been used to get the principal stress in a test of multiaxial fatigue and inserted them in the von mises theory to get the suitable value of torsion with cycling bending stress. In the experimental part it was needed to manufacture multiaxial fatigue test machine to find the non-proportional fatigue properties of testing metals which have different mechanical behavior to identify the life of fatigue of metals and shape of the resulting fracture after exposing specimens to either reversed bending for verification the experimental results and combined bending with torsion stresses for L690M steel, C26800 brass, copper and 2117-T4 Aluminum in multi axial fatigue. The results show that when taking the stress ratio (λ = τ /σa ) constant for all metals used in this study, it was found that copper and 2117-T4 aluminum is the most resistant to multi axial fatigue failure, while C26800 brass, and L690M steel have less resistance It is clear from the surface fracture of the specimens’ that multiaxial fatigue will effect on the orientation of maximum Shear stress and its values which inclined the crack evolution when compared with the axial fatigue

Keywords: Multi Axial Fatigue Failure etc.

Article published in International Journal of Current Engineering and Technology, Vol.7, No.1 (Feb-2017)