PSI - Issue 72

Levente Tatár et al. / Procedia Structural Integrity 72 (2025) 345–353

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Fig. 8: a) Global view of specimen b) Eng. stress – strain curves for realistic model matching experiment.

The best matching derived flowcurves for the idealistic and the realistic model, as well as the Considère limit curve can be seen in Fig. 9. This figure shows, how quite small differences in flow curve can result in large differences in post-necking behaviour.

Fig. 9. Final flowcurves

4. Conclusions The present work has proven the validity of the Considère criterion as a limit curve. It shows, that the post-necking behaviour of tensile test is very sensitive to input data. Small variations of the plastic flowcurve may lead to large differences in the result. On the other hand, extremely small variations of the geometry (even with idealized material properties) may lead to off-center necking and substantially different post-necking behaviour. This indicates that extra care has to be taken when plastic flowcurves are used for stresses/strains over necking limit for the material. Further investigations are required to clarify these effects. Acknowledgements The research is based on work funded by the Thematic Excellence Programme 2020 (2020-4.1.1.-TKP2020) supported by the Ministry of Innovation and Technology of Hungary.