PSI - Issue 18

Tintu David Joy et al. / Procedia Structural Integrity 18 (2019) 287–292 T. D. Joy, G. Kullmer./ Structural Integrity Procedia 00 (2019) 000–000

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The method to initiate crack automatically is tested mostly in simple models and specimens. In the future this shall also be tested in complex models such as a bicycle stem as in Joy et al. (2018), so as to calculate the total lifetime of the structure. In addition, the crack initiation in A DAPCRACK 3D could also be tested using compact-specimens that are provided in Reschetnik et al. (2017) to investigate the possibility of crack initiation several times. The compact tension specimens which are used for the simulations in Reschetnik et al. (2017) are created with holes and notches within the geometry to investigate their influence on crack propagation and thereby extending the lifetime of the structure. The results obtained from A DAPCRACK 3D can also be compared with the experimental results in Reschetnik et al. (2017). 5. Conclusion The architecture of A DAPCRACK 3D was updated by implementing a new module, namely C RACKINT 3D. The procedure to initiate a crack in 3D structures is successfully integrated in the module and tested with various 3D models. For instance, in the example of 3D knee-lever, the origin of crack and direction of crack initiation showed good agreement with that of the reference model of 3D knee-lever shown in Schöllmann (2003). The testing of the new procedure with additional 3D specimens was also successful in the automatic crack initiation. For the automatic crack initiation in the A BAQUS TM model, the software A DAPCRACK 3D interacts with the model through APIs provided in A BAQUS TM scripting interface. The APIs provided by A BAQUS TM prove to be very effective and comparatively easy to edit the model and to retrieve data from the model. Python scripts developed for this purpose are integrated in the module C RACKINT 3D. Further investigations shall be performed to compare the simulated data with the experimental results. Abaqus, V.6.14, 2014. Documentation, Dassault Systemes Simulia Corporation, 651. Buchholz, F-G., Just, V., Richard, H. A., 2005. Computational simulation and experimental findings of three ‐ dimensional fatigue crack growth in a single ‐ edge notched specimen under torsion loading, Fatigue & Fracture of Engineering Materials & Structures 28.1 ‐ 2, 127-134. Chan, K. S., 2010. Roles of microstructure in fatigue crack initiation, International Journal of Fatigue, 32, 1428-1447. Fulland, M., Richard, H. A., Sander, M., Kullmer, G., 2006. Fatigue crack propagation in the frame of a hydraulic press, Crack Path. Haibach, E., 2006. Betriebsfestigkeit, Springer-Verlag, Berlin, 156, 264, 536. Hou, J., Goldstraw, M., Maan, S., Knop, M., 2001. An Evaluation of 3D Crack Growth using Zencrack, DSTO Aeronautical and Maritime Research Laboratory. Ingraffea, A. R., Carter, B. J., Wawrzynek, P. A., 2003. Automated 3D Crack Growth Simulation, Cornell University, Ithaca, NY, USA. Joy, T. D., Brüggemann, J.–P., Kullmer, G., 2018. Crack growth simulation with Adapcrack3D in 3D structures under the influence of temperature, Procedia Structural Integrity, 13, 328-333. Läpple, V., 2011. Einführung in die Festigkeitslehre, Springer Vieweg, Wiesbaden, 289-291. Radaj, D., Vormwald, M., 2007. Ermüdungsfestigkeit, Springer-Verlag, Berlin, 191-193. Reschetnik, W., Brüggemann, J.–P., Richard, H. A., Kullmer, G., Risse, L., 2017. Beeinflussung des Risswachstums durch Kerben in additiv gefertigten Strukturen, In Additive Fertigung von Bauteilen und Strukturen, Springer Vieweg, Wiesbaden, 189-200. Richard, H. A., Sander, M., Fulland, M., Kullmer, G., 2008. Development of fatigue crack growth in real structures, Engineering Fracture Mechanics, 75(3-4), 331-340. Richard, H. A., Sander, M., Schramm, B., Kullmer, G., Wirxel, M., 2013. Fatigue crack growth in real structures, International Journal of Fatigue, 83-88. Sangid, M. D., 2013. The physics of fatigue crack initiation, International journal of fatigue, 57, 58-72. Schöllmann, M., Fulland, M., Richard, H. A., 2003. Development of a new software for adaptive crack growth simulations in 3D structures, Engineering Fracture Mechanics, 70, 249-268. Smith, K. N., Topper, T., Watson, P., 1970. A stress-strain function for the fatigue of metals, Journal of materials, 5, 767-778. References