The mean stress and phase angle effect on multiaxial fatigue behavior of a TiAl alloy: Failure analysis and life modeling. (1st March 2021)

• Record Type: Journal Article
• Authors: Zhang, Qiang; Hu, Xiaoan; Zhang, Ziruo; Sun, Tong; Wu, Jinwu; Li, Yifan; Ren, Tingting
• Is Part Of: International journal of mechanical sciences. Volume 193(2021)
• Publication Date: 2021-03-01
• Subjects: TiAl alloy -- Multiaxial fatigue -- Phase angle -- Mean stress -- Critical plane criterion -- Life prediction method; Mechanical engineering -- Periodicals; Génie mécanique -- Périodiques; Mechanical engineering; Maschinenbau; Mechanik; Zeitschrift; Periodicals; 621.05
• DOI: 10.1016/j.ijmecsci.2020.106123
• Languages: English
• ISSNs: 0020-7403

Abstract

Highlights: Non-zero σm has enhanced the impact of phase angle on CTT multiaxial fatigue lives. S-L criterion is extended to description fatigue limit of multiaxial fatigue with 0< ρ <1. The overestimated effect of σm on multiaxial fatigue life is corrected by factor K. Proposed life prediction method is of good accuracy for CTT experimental results. Abstract: In the presence of multiaxial fatigue loadings with multiple loading variables, fatigue behavior of material differs from those under in-phase (IP) multiaxial fatigue loadings. The co-existence of non-zero mean stress and phase angle could be extremely harmful to fatigue resistance of material. In this case, it is vital for researchers engaging in relative fields to put forward capable life prediction methods. In this study, the mechanical property of a TiAl alloy under combined tension-torsion (CTT) fatigue loadings is investigated through experiments. The applied fatigue load contains non-zero mean stress components as well as phase angle components. The fracture of specimen is observed by scanning electron microscope (SEM) to investigate the correspondence between multiaxial fatigue life and failure behavior. Susmel and Lazzarin's (S-L) fatigue criterion is critically reviewed to put forward a modification on its intrinsic drawback. In parallel, a correction factor is introduced to make the modified Wӧhler curve method (MWCM) feasible for multiaxial fatigue life prediction with multiple loading variables. Verified by experimental results of present work, the proposed method is of good accuracy compared with Matake method and McDiarmid method. Graphical abstract: On the basis of extended S-L criterion and introduced correction factor K, fatigue life prediction results of CTT experimental results with multiple loading variables are of good accuracy. Image, graphical abstract