PSI - Issue 42

A. Sulamanidze et al. / Procedia Structural Integrity 42 (2022) 412–419 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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results observed in Fig. 8a refers to the first five loading cycles. Obviously, such comparisons will require much more computing resources with an increase in the number of accumulated cycles of thermo-mechanical loading. Figure 8b demonstrates the effect of applied load level on changes in stress-strain response curves at OOP TMF cycles. In addition, the shape of these curves will depend on and change with the number of deformation cycles. This suggests that the applicability of the modified compliance method (Ewest, 2016) to elastic stress intensity factor determination is questionable. The convenience of the proposed algorithm for multi-physics calculations is that it allows one to reveal the decomposition of total strains into elastic, nonlinear, and thermal components according to Eq. (2). This circumstance is very useful from the point of view of interpreting experimental data on the TMF crack growth rate. Figures 8c and 8d represent the plots for thermo-mechanical elastic- plastic strains behaviour under IP (σ nom,max = 80 MPa) and OOP (σ nom,max = 200 MPa) TMF conditions in the SENT specimen with the crack length 5mm. Further details regarding the computation conditions are found in the legends of Fig. 7. It can be seen that, the equivalent von Mises, total and elastic-plastic strains versus timing during heating differs from their values during cooling. 5. Conclusions In this study a new algorithm for the multi-physics numerical calculations developed and implemented incorporates Maxwell 3D, Fluent and Transient Structural modules of ANSYS 2021R1. This algorithm was applied to the analysis of temperature distribution and local elastoplastic stresses and strains to simulate the conditions of in-phase and out of-phase thermo-mechanical fatigue loading. The comparison multi-physics FE-analysis and direct measurements by infra-red camera and COD shown is intended to contribute to a better understanding of the different mechanisms driving TMF crack growth and the address the outstanding questions associated with basic methodology. References Stekovic S., Jones J.P., Engel B., Whittaker M.T., Norman V., Rouse J.P., Pattison S., Hyde C.J., Härnman P., Lancaster R.J., Leidermark D., Moverare J., 2020. DevTMF – Towards code of practice for thermo-mechanical fatigue crack growth. International Journal of Fatigue 138, 105675. Pretty, C. J., Whitaker, M. T., Williams, S. J., 2017. Thermo-mechanical fatigue crack growth of RR1000. Materials 10(1), 34 Jones J., Whittaker M., Lancaster R., Hyde C., Rouse J., Engel B., Pattison S., Stekovic S., Jackson C., Li H.Y., 2020. The effect of phase angle on crack growth mechanisms under thermomechanical fatigue loading. International Journal of Fatigue 135, 105539. Norman V., Stekovic S., Jones J., Whittaker M., Grant B., 2020. On the mechanistic difference between in-phase and out-of-phase thermomechanical fatigue crack growth. International Journal of Fatigue 135, 105528. Palmert F., Moverate J., Gustafsson D., 2019. Thermomechanical fatigue crack growth in a single crystal nickel base superalloy. International Journal of Fatigue 122, pp. 184. Engel, B., Rouse, J.P., Hyde, C.J., Lavie, W., Leidermark, D., Stekovic, S., Williams, S.J., Pattison, S.J., Grant, B., Whittaker, M.T., Jones, J.P., Lancaster, R.J., Li, H.Y., 2020. The prediction of crack propagation in coarse grain RR1000 using a unified modelling approach. International Journal of Fatigue 137, 105652. Ewest, D., Almroth, P., Sjödin, B., Simonsson, K., Leidermark, D., Moverare J., 2016. A modified compliance method for fatigue crack propagation applied on a single edge notch specimen. International Journal of Fatigue 92, pp. 61. Fischer, C., Schweizer, C., Seifert, T., 2016. A crack opening stress equation for in-phase and out-of-phase thermomechanical fatigue loading. International Journal of Fatigue 88, pp. 178. Feulvarch E., Lacroix R., Madon K., Deschanels H., Pignol M., 2021. 3D XFEM investigation of the plasticity effect on fatigue propagation under thermo-mechanical loading. International Journal of Fracture 230, pp. 33. Karabela, A.; Zhao, L.G.; Lin, B.; Tong, J.; Hardy, M.C., 2013. Oxygen diffusion and crack growth for a nickel-based superalloy under fatigue oxidation conditions. Materials Science and Engineering 567, pp. 46. ANSYS Academic Research Electronics, Fluent, Mechanical APDL Release 2021 R1, ANSYS, Inc.