PSI - Issue 13

T. D. Joy et al. / Structural Integrity Procedia 00 (2018) 000 – 000

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T.D. Joy et al. / Procedia Structural Integrity 13 (2018) 328–333

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The mechanical and temperature loadings are assumed to be proportional to one another. Since the stresses are read at the same time there is no additional criterion required to simulate the influence of two different loadings on mixed mode situations. Experiments can be performed to understand the effect of non-proportional loadings on mixed-mode loading situations. This can be used to create a new criterion if necessary to simulate the crack growth in case of non-proportional loading situations. Likewise, the material data which was used for the simulations in this paper is obtained from experiments without considering the influence of temperature. Thus experiments with various temperature boundary conditions can be conducted to create new crack propagation curves to obtain material data which shows the influence of temperature. The results obtained from experiments can be incorporated to extend the functionality of A DAPCRACK 3D further. The lifetime of models is generally calculated in A DAPCRACK 3D without considering the lifetime required to initiate a crack. The crack initiation lifetime is also not considered in the examples presented in this paper. It is possible to introduce the P swt -damage parameter, see Smith et al. (1970) or the Morrow’s approach, see Morrow (1968) to calculate the lifetime required to initiate a crack in the model. The introduction of a new boundary condition in A DAPCRACK 3D, namely the temperature boundary condition was successfully implemented and tested by using the model of a Y-strainer. The direction of crack growth and crack path in case of a model with temperature boundary condition showed distinct influences compared to a model simulated only with mechanical loading conditions. Likewise in this case the cyclic comparative stress intensity factor also had a bigger value when the model has an additional boundary condition, depicting the influence of temperature on the structure. Thus A DAPCRACK 3D can simulate two different proportional loading situations. Further studies are required to integrate the non-proportional loading situations as well as to obtain the material data considering the temperature boundary conditions which all can be achieved with the help of experiments. Brüggemann, J.-P.; Risse, L., Grübel, A., Richard, H. A., Kullmer, G., 2018. Validierung der strukturmechanischen Funktionsfähigkeit additiv gefertigter Leichtbaustrukturen durch experimentelle Bauteilprüfungen. In: DVM-Bericht 250, Arbeitskreis: Bruchmechanische Werkstoff- und Bauteilbewertung: Beanspruchungsanalyse, Prüfmethoden und Anwendungen, Deutscher Verband für Materialforschung und -prüfung e.V., Paderborn, 89-98. DIN EN ISO 4210-5:2014: Fahrräder – Sicherheitstechnische Anforderungen an Fahrräder – Teil 5: Prüfverfahren für die Lenkung (ISO 4210 5:2014). Deutsche Fassung EN ISO 4210-5:2014. Dobrzanski, J., 2003. Internal damage processes in low alloy chromium-molybdenum steels during high-temperature creep service, Journal of Materials Processing Technology, 157, 297-303. Klueh, R. L., 1982. Chromium-molybdenum steels for fusion reactor first walls – a review, Nuclear Engineering and Design, 72, 329-344. Morrow, J., 1968. Fatigue properties of metals, Fatigue Design Handbook, section 3.2. Palcer, J.A., 1953. Y-type strainer, US Patent 2, 657,805. Richard, H. A., Sander, M., Schramm, B., Kullmer, G., Wirxel, M., 2013. Fatigue crack growth in real structures, International Journal of Fatigue, 83-88. Richard, H. A., Fulland, M., Sander, M., Kullmer, G., 2005. Fracture in a rubber-sprung railway wheel. Engineering Failure Analysis, 12, 986-999. Richard, H. A., and Sander, M. Fulland, M., Kullmer, G., 2008. Development of fatigue crack growth in real structures 75, 331-340. Schöllmann, M., Fulland, M., Richard, H. A., 2003. Development of a new software for adaptive crack growth simulations in 3D structures, 70, 249-268. Schöllmann, M., Kullmer, G., Fulland, M., Richard, H. A., 2001. A new criterion for 3D crack growth under mixed-mode (I+II+III) loading, Proceedings of the 6th International Conference on Biaxial/Multiaxial Fatigue & Fracture, Lisbon, 589 – 96. Schöllmann, M., Richard, H. A., Kullmer, G., Fulland M., 2002. A new criterion for the prediction of crack development in multiaxially loaded structures, International Journal of Fracture, 117, 129-141. Smith, K. N., Watson, P. and Topper, T. H., 1970. A stress-strain function for the fatigue of materials, Journal of Materials, 5, 767-778. 5. Conclusion References Brüggemann, J.-P., Risse, L., Kullmer, G., Richard, H. A., 2017. Vergleich zweier Optimierungsstrategien am Beispiel additiv gefertigter Rennradvorbauten. In: DVM-Bericht 402, Arbeitskreis: Additiv gefertigte Bauteile und Strukturen, Deutscher Verband für Materialforschung und -prüfung e.V., Berlin, 49-66.