0
Research Papers

Development of a Multiaxial Fatigue Damage Model for High Strength Alloys Using a Critical Plane Methodology

[+] Author and Article Information
Matthew Erickson

Department of Mechanical Engineering, North Dakota State University, Fargo, ND 58105

Alan R. Kallmeyer1

Department of Mechanical Engineering, North Dakota State University, Fargo, ND 58105

Robert H. Van Stone

 General Electric Aviation, Evendale, OH 45215

Peter Kurath

Department of Mechanical Science and Engineering, University of Illinois, Urbana, IL 61801

1

Corresponding author.

J. Eng. Mater. Technol 130(4), 041008 (Sep 11, 2008) (9 pages) doi:10.1115/1.2969255 History: Received November 14, 2007; Revised May 27, 2008; Published September 11, 2008

The prediction of fatigue life for metallic components subjected to complex multiaxial stress states is a challenging aspect in design. Equivalent-stress approaches often work reasonably well for uniaxial and proportional load paths; however, the analysis of nonproportional load paths brings forth complexities, such as the identification of cycles, definition of mean stresses, and phase shifts, that the equivalent-stress approaches have difficulties in modeling. Shear-stress based critical-plane approaches, which consider the orientation of the plane on which the crack is assumed to nucleate, have shown better success in correlating experimental results for a broader variety of load paths than equivalent-stress models. However, while the interpretation of the ancillary stress terms in a critical-plane parameter is generally straightforward within proportional loadings, there is often ambiguity in the definition when the loading is nonproportional. In this study, a thorough examination of the variables responsible for crack nucleation is presented in the context of the critical-plane methodology. Uniaxial and multiaxial fatigue data from Ti–6Al–4V and three other alloys, namely, Rene’104, Rene’88DT, and Direct Age 718, are used as the basis for the evaluation. The experimental fatigue data include axial, torsional, proportional, and a variety of nonproportional tension/torsion load paths. Specific attention is given to the effects of torsional mean stresses, the definition of the critical plane, and the interpretation of normal stress terms on the critical plane within nonproportional load paths. A new modification to a critical-plane parameter is presented, which provides a good correlation of experimental fatigue data.

FIGURES IN THIS ARTICLE
<>
Copyright © 2008 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Biaxial load paths for one complete cycle in normal/shear-stress space

Grahic Jump Location
Figure 2

Findley parameter applied to (a) uniaxial and (b) biaxial Ti–6Al–4V fatigue data

Grahic Jump Location
Figure 3

Calculated versus experimental life for Ti–6Al–4V using the Findley parameter. The dashed lines represent unity and a factor of 2.

Grahic Jump Location
Figure 4

Effect of mean shear stress on torsional fatigue strength: (a) shear-stress amplitude and (b) modified shear-stress amplitude versus cycles to failure. The solid and dashed lines represent curve fits to the R=0.1 and R=−1 data, respectively.

Grahic Jump Location
Figure 5

Load paths on plane of maximum shear-stress amplitude for five specimens with similar shear amplitudes

Grahic Jump Location
Figure 6

Normal and shear stresses versus time on the max shear amplitude plane for one cycle of a check-path specimen

Grahic Jump Location
Figure 7

Modified damage parameter applied to (a) uniaxial and (b) multiaxial Ti–6Al–4V fatigue data

Grahic Jump Location
Figure 8

Calculated versus experimental life for Ti–6Al–4V using the proposed damage parameter on the maximum shear amplitude plane. The dashed lines represent unity and a factor of 2.

Grahic Jump Location
Figure 9

Calculated versus experimental life for Rene104 using (a) the Findley parameter and (b) the proposed damage parameter. The dashed lines represent unity and a factor of 2.

Grahic Jump Location
Figure 10

Calculated versus experimental life for Rene’88 using (a) the Findley parameter and (b) the proposed damage parameter. The dashed lines represent unity and a factor of 2.

Grahic Jump Location
Figure 11

Calculated versus experimental life for DA 718 using (a) the Findley parameter and (b) the proposed damage parameter. The dashed lines represent unity and a factor of 2.

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In