Effect of Artificial Defect and Mean Shear Stress on Torsional Fatigue Behaviour

Abstract:

The aim of this work is to study the influence of artificial defect and mean stress on fatigue strength under torsion loading. Spherical artificial defects have been machined at the surface of gauge length of fatigue samples. Experimental investigations conducted on both defective and defect free materials. The crack initiation mechanisms have been identified based on several observations on Scanning Electron Microscope (SEM) at different stage of fatigue life. It is observed that the defect free material subjected to torsion loading allows relatively earlier initiation. Experimental results show that mean shear stress has no effect on fatigue behaviour under torsion loading. It is also concluded that defects are much more damaging in high cycle fatigue regime than in low cycle fatigue one.

• Periodical: Applied Mechanics and Materials (Volume 146)
• Pages: 74-82
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.146.74
• Online since: December 2011
• Authors: Anouar Nasr, Yves Nadot, Chokri Bouraoui, Raouf Fathallah
• Keywords: Artificial Defect, Fatigue, Mean Shear Stress, Torsion

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