PSI - Issue 42

Lucas Mangas Araújo et al. / Procedia Structural Integrity 42 (2022) 1591–1599 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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Fig. 7. Comparison between the numerical responses of Mises and Gao based formulations with the experimental reaction curve from the compression- tension (−90◦ to+90◦) test 1 after recalibration. On the left, only is activated, while on the left both and are considered.

Fig. 8. Comparison between the numerical responses of Mises and Gao based formulations with the experimental reaction curve from the shear shear (−0 ◦ to + 0◦) test 1 after recalibration. On the left, only is activated, while on the left both and are considered. 4. Conclusions In this contribution, the influence of the stress invariants ( 1 and 3 ) on the Ductile Fracture and Ultra-Low Cycle fatigue behavior of metallic materials was investigated. The alloy analyzed was the SAE 1045 steel due to the vast experimental data availability on this material, in addition to its industrial relevance. A Gao-based model with mixed hardening was proposed to capture the pressure and third invariant effects, whose parameters were calibrated based on data furnished by Bai [1]. The modeling considered a mixed hardening approach because it recovers isotropic and kinematic hardening as limiting cases. A numerical scheme is elaborated to simulate the SAE 1045 steel response under different loading conditions. Furthermore, an optimization technique is used to identify the isotropic hardening law based on the standard smooth cylindrical tension test. In section 5, one demonstrates that traditional Mises constitutive modeling fails to describe the monotonic behavior ( ≠ 1/3 and ≠ 1 ) other than the calibration