2. Reference solution#

2.1. Benchmark results#

The results are experimental [ref 1]. The measured values are the stress amplitudes after stabilization:

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\(\frac{\Delta {\varepsilon }_{\mathit{xx}}}{2}\)

\({\varepsilon }_{\mathit{moy}}\)

\(\frac{\Delta {\sigma }_{\mathit{xx}}}{2}\)

\({\sigma }_{\mathit{moy}}\)

\(\frac{\Delta \gamma }{2}\)

\({\gamma }_{\mathit{moy}}\)

\(\frac{\Delta {\sigma }_{\mathit{xy}}}{2}\)

\({{\sigma }_{\mathit{xy}}}_{\mathit{moy}}\)

FRI15

0.0034

0

0

413

413

-5

0.0058

0

237

0

FRI15

0.0034

0

0

398

398

-5

0.0058

0

231

1

So we get the following averages \(\frac{\Delta {\sigma }_{\mathit{xx}}}{2}\mathrm{=}405.5\mathit{MPa}\) and \(\frac{\Delta {\sigma }_{\mathit{xy}}}{2}\mathrm{=}234\mathit{MPa}\),

which, like \({\sigma }_{\mathit{xx}}\mathit{moy}\mathrm{=}\mathrm{-}5\mathit{Mpa}\), and \({\sigma }_{\mathit{xx}}\mathit{moy}\mathrm{=}\mathrm{0,5}\mathit{Mpa}\) leads to:

\({\sigma }_{\mathit{xx}}\mathit{max}\mathrm{=}400.5\mathit{MPa}\), \({\sigma }_{\mathit{xx}}\mathit{min}\mathrm{=}\mathrm{-}410.5\mathit{MPa}\)

\({\sigma }_{\mathit{xy}}\mathit{max}\mathrm{=}234.5\mathit{MPa}\), \({\sigma }_{\mathit{xy}}\mathit{min}\mathrm{=}\mathrm{-}233.5\mathit{MPa}\)

2.2. Uncertainty about the solution#

The uncertainty resulting from the variability of the experimental results is 2%. That which comes from the identification of material parameters can be estimated at 5% to 10% (cf. [ref. 2]).

2.3. Bibliographical references#

  1. « Multiaxial fatigue evaluation using discriminating strain paths » Nima Shamsaei, Ali Fatemi, Darrell F. Socie International Journal of Fatigue 33 (2011) 597—609

  2. J.M. PROIX « Viscoplastic behavior taking into account the non-proportionality of the load » EDF R&D-CR- AMA12 -284, 12/12/12